Armen Zambranomozci 0.15.1: Buildbot Bridge support + bug fixes

It's been a while since our last announced released and I would like to highlight some of the significant changes since then.
A major highlight for the latest release is the support to schedule Buildbot jobs through TaskCluster making use of the Buildbot Bridge. For more information about this please read in here.


@nikkisquared is our latest contributor who landed more formalized exceptions and error handling. Thanks!
As always, many thanks to @adusca and @vaibhavmagarwal for their endless contributions.

How to update

Run "pip install -U mozci" to update

New Features

  • Query Treeherder for hidden jobs
  • BuildbotBridge support
    • It allows submitting a graph of Buildbot jobs with dependencies
    • The graph is submitted to TaskCluster

Minor changes

  • Fix backfilling issue
  • Password prompt improvements
  • More specific exceptions
  • Skip Windows 10 jobs for talos

All changes

You can see all changes in here:

Creative Commons License
This work by Zambrano Gasparnian, Armen is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported License.

Armen ZambranoMozilla CI tools contribution opportunities

A lot of feature development has happened around Mozilla CI tools this year and it has been great to have so many contributors to help us move forward! We would not be here without all the many contributions we've had.

For now, MozCI needs to wait a bit before we can do full progress around TaskCluster support (blocked on big-graph scheduling work )

Some of the work where we could get some help until then is the following:
There are more issues, however, I believe these are easier to contribute to.

Feel free to ping "armenzg" on IRC at the #ateam channel (Read more on how to contact us in here)

Creative Commons License
This work by Zambrano Gasparnian, Armen is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported License.

Andreas TolfsenMaking Mercurial log make sense

If you’re into Mercurial bookmarks, hailed as the Mercurial equivalent to git bookmarks, my excellent colleague Andrew Halberstadt has written an extension that returns commits associated with a particular bookmark called bookbinder.

In his own words, “[a] book binder is a person or machine [that] binds pages to books. In a similar vein, bookbinder binds commits to bookmarks”. It does this by implementing a feature revset allowing bookbinder to subvert all commands that have a REV argument and replace any detected bookmark names with the feature revset.

This normally works by passing the name of your bookmark to any command that supports bookmarks, e.g. hg log -r BOOKMARK, and it will then replace BOOKMARK with a revset containing all changesets “within” this bookmark.

Because the stock hg log doesn’t make much sense to me, especially without passing --graph to graphically display the repository’s DAG, I highly recommend having a look at it to give hg log back some sanity.

Since I never get around to clean up my bookmarks, it would be quite convenient to instruct bookbinder to show me the commits associated with the bookmark of my latest commit.

For this I’ve added an alias to my .hgrc that tells it to pick the bookmark from my last commit, or tip:

blog = log --rev 'feature(tip)'

If I have three commits on my bookmark, this will return something akin to what you would expect from git log:

% hg blog
changeset:   267448:66fae38273f2
bookmark:    bug_1202663_super
tag:         tip
user:        Andreas Tolfsen
date:        Tue Oct 13 16:52:26 2015 +0100
summary:     Bug 1213797: Refactor screen capture and SVG document support

changeset:   267447:3cc8741649af
user:        Andreas Tolfsen
date:        Fri Oct 09 12:02:42 2015 +0100
summary:     Bug 1202663: Use dispatcher for screen capture command in listener

changeset:   267446:880e2bdb24ff
parent:      267426:607a236c2299
user:        Andreas Tolfsen
date:        Tue Oct 13 16:58:40 2015 +0100
summary:     Bug 1213800: More exhaustive Marionette screen capture tests

Robert KaiserShortening Crash Signatures: Dropping Argument Lists

Crash signatures derived from the function on the stack are how we group ("bucket") crashes as belonging to a certain issue or bug. They should be precise enough to identify this "bucket" but also short enough so we can handle it as a denominator in lists and when talking about those issues. For some time, we have seen that our signatures are very long-winded and contain parts that make it sometimes even harder to bucket correctly. To fix that, we set out to shorten our crash signatures.

We already completed a first step of this effort in June: After we found that templates in signatures were often fluctuating wildly in crashes that belonged to the same bug, all <sometemplate> parts of crash signatures were replaced by just <T>.

That made a signature like this (from bug 1045509, the [@ …] are our customary delimiters for signatures, not really part of the signature itself though):
[@ nsTArray_base<nsTArrayFallibleAllocator, nsTArray_CopyWithMemutils>::UsesAutoArrayBuffer() | nsTArray_Impl<unsigned char, nsTArrayFallibleAllocator>::SizeOfExcludingThis(unsigned int (*)(void const*)) ]

be shortended to:
[@ nsTArray_base<T>::UsesAutoArrayBuffer() | nsTArray_Impl<T>::SizeOfExcludingThis(unsigned int (*)(void const*)) ]

Which is definitely somewhat better to read and put in tables like topcrash reports, etc. - and we found it did not munge bugs together into the same signature more than previously, at least to our knowledge.

But we found out we can go even further: Different argument lists of functions (mostly due to overloading) did as far as I remember not help us distinguish any bugs in the >4 years I have been working with crashes - but patches changing types of arguments or adding one to a function often made us lose the connection between a bug and the signature. Therefore, we are removing argument lists from the signatures.

The signature listed above will turn out as:
[@ nsTArray_base<T>::UsesAutoArrayBuffer | nsTArray_Impl<T>::SizeOfExcludingThis ]

Today, we have run a script on Bugzilla (see bug 1178094) to update all affected bugs to add the new shortened signature to the Crash Signatures field without sending a ton of bugmail.

We have tested in the last weeks that Socorro crash-stats can create the new shortened signatures fine on their staging setup and that generation of the special "shutdownhang | …" signatures for browser processes that did take more than 60s to shut down and "OOM | …" for out-of-memory crashes do still work in all cases where they worked before.

As all preparation has been done, we will flip the switch on production Socorro crash-stats in the next days, and then those shortened signatures will be created everywhere.

Note that this will impede some stats that are comparing signatures across days, even though we will see to reprocess some crashes to make the watershed be at a UTC day delimiter so that as few stats as possible are disturbed by the change.

Please let me know of any issues with those changes (as well as any other questions about or issues with crash analysis), and thanks to Lars, Byron (glob) and others who helped with those changes!

Mozilla FundraisingEOY Fundraising Preview: Getting Ready

“We’ve always felt people should be in control of their online lives, not kept in the dark. We want the tools we build — like Firefox — to respect people, to care about their security and to protect their privacy. … Continue reading

Air MozillaMartes mozilleros

Martes mozilleros Reunión bi-semanal para hablar sobre el estado de Mozilla, la comunidad y sus proyectos. Bi-weekly meeting to talk (in Spanish) about Mozilla status, community and...

Yunier José Sosa VázquezEl futuro de los plugins NPAPI en Firefox

Esta es una traducción del artículo original publicado en el blog Future Releases. Escrito por Benjamin Smedberg .

Mozilla ha ido mejorando constantemente su plataforma Web para apoyar características que antes sólo estaban disponibles a través de plugins NPAPI. Características como el video en vivo (streaming) y, los gráficos avanzados y de juegos se han convertido en APIs Web nativas en los últimos años. Mozilla sigue dando prioridad a características que harán posible a los sitios poder funcionar sin plugins. Características tales como el acceso al portapapeles que solían requerir plugins, ahora están disponibles a través de las API Web nativas. ¿A qué se debe esto? A que los navegadores y la Web han crecido y NPAPI ha mostrado su edad. Los plugins son una fuente de problemas de rendimiento y de accidentes e incidentes de seguridad para los usuarios de la Web.

Mozilla tiene la intención de eliminar el soporte para la mayoría de los plugins NPAPI en Firefox antes de finales de 2016. Firefox comenzó este proceso hace varios años (EN) con la activación manual de plugins, permitiendo a los usuarios activar los plugins sólo cuando creen que son necesarios. Esta decisión refleja las acciones de los otros navegadores modernos, como Google Chrome y Microsoft Edge, que ya han eliminado el soporte para NPAPI. Además, dado que las nuevas plataformas de Firefox no tienen que soportar un ecosistema existente de usuarios y plugins, las nuevas plataformas de 64 bits de Firefox para Windows funcionarán sin soporte para plugins.


Activación manual de plugins en Firefox

Debido a que Adobe Flash es todavía una parte común de la experiencia en la Web para la mayoría de los usuarios, vamos a seguir siendo compatibles con Flash dentro de Firefox como una excepción a la política de complementos en general. Mozilla y Adobe continuarán colaborando para traer mejoras a la experiencia de Flash en Firefox, incluyendo la estabilidad y el rendimiento, las características y la arquitectura de seguridad.

Como parte de nuestra estrategia de plugin, Mozilla y Unity están orgullosos de anunciar una estrecha colaboración y un plan en conjunto que permitirá contenido basado en Unity para ser reproducido directamente en el navegador sin necesidad de plugins. Como esta tecnología sigue evolucionando, Unity ha anunciado (EN) un plan de trabajo actualizado para su tecnología Web Player.

Los sitios Web y editores que actualmente utilizan plugins como Silverlight o Java deben acelerar su transición a tecnologías web. La plataforma Web es de gran alcance y por lo general se puede hacer todo lo que un plugin puede hacer. En los raros casos en que un sitio tiene que extender las tecnologías Web, la solución recomendada es desarrollar las características adicionales como un complemento de Firefox. Los mantenedores de sitios deben prepararse para que los plugins dejen de funcionar en todas las versiones de Firefox para finales de 2016.

Mozilla continúa trabajando con Oracle Java Platform Group para asegurar una transición sin problemas para los sitios web que utilizan Java. Para más información de Oracle acerca de los planes de transición de Java pueden remitirse a este artículo (EN) de Oracle Team. Oracle recomienda (EN) que los sitios que utilizan actualmente los applets de Java consideren cambiar a plugins libres tales como Java Web Start.

El equipo de Mozilla quiere trabajar en estrecha colaboración con los editores afectados para que su transición sea lo menos problemática posible. La Web proporciona un entorno cada vez más rico que debería eliminar la necesidad de plugins, y estamos ansiosos por seguir mejorando la plataforma Web para cualquier caso donde aún pueden ser necesarios plugins para su uso. Para plantear una discusión o pregunta sobre el futuro de los plugins en Firefox pueden dirigirse a lista de desarrollo de plugins de Mozilla (EN).

¿Y ustedes qué opinan? ¿Les parece bien que Firefox siga trabajando con Flash Player? ¿Qué creen de la activación manual de plugins?

Fuente: Mozilla Hispano

Byron Joneshappy bmo push day!

the following changes have been pushed to : user fields are cleared when navigating back to a page (eg. after an error) : help docs not available for User Preferences : gravatar container for comment 0 can be too wide : Button edges are hard to see at most zoom-levels, with bmo “experimental user interface” : Buttons besides ‘User Story’ overflow if the user story is a one-liner : linkification isn’t applied to the user-story field : Make login UX mobile friendly to assist mobile authentication workflow : BMO login being reset for every browser session : make the TOTP MFA code field type=number on mobile : Release Tracking Report doesn’t return bugs with tracking flags set to — when searching for “not fixed” values : Update crash signatures to match new Socorro signature generation : cannot remove other people from the cc list : Remember expanded/collapsed sections : Always show “never email me about this bug” checkbox : needinfo requests where the current user is the requestee shouldn’t be editable : add support for duo-security

Filed under: bmo, mozilla

Christian Heilmann16 Questions you need to answer before you give a conference talk

When it comes to giving a talk at a conference the thing people freak out the most about is the delivery. Being in front of a large audience on stage is scary and for many people unthinkable.


I don’t want to discourage anyone to do this – it is amazing and it feels great to inspire people. The good news is that by covering the things here you will go on stage with the utmost confidence and you will dazzle.

I wanted to note down the things people don’t consider about presenting at conferences. There is no shortage of posts claiming that evangelism is “only presenting at conferences”. Furthermore it is deemed only worth-while when done by “real developers who work on the products”. This is the perfect scenario, of course. Before you judge “just presenting” as a simple task consider the following questions. If you are a professional presenter and evangelist you need to have them covered. More importantly, consider the time needed to do that work and how you would fit it into your daily job of delivering code.

  1. 1) Do you know the topic well enough?
  2. 2) Are you sure about your facts?
  3. 3) Are you aware of the audience?
  4. 4) What’s your story line? How do you package the idea?
  5. 5) Where are the materials you talk about?
  6. 6) Are you sure you can release the talk the way you wrote it?
  7. 7) When are the materials due?
  8. 8) What does the conference need from you?
  9. 9) How do you get to the event?
  10. 10) Do you have all you need? Is everything going to be fine while you’re gone?
  11. 11) Who pays what – how do you get your money back?
  12. 12) Can you afford the time? Do you need to extend your trip to make it worth while?
  13. 13) Have you prepared for a presentation in the conference environment?
  14. 14) How do you measure if this was a success?
  15. 15) How do you make this re-usable for your company?
  16. 16) Are you ready to deal with the follow-up?

1) Do you know the topic well enough?

If you talk about your own product, this is easy. It is also easy to be useless. Writing a demo for a talk that can’t fail is cheating. It is also hard to repeat for the audience. It is a theoretical exercise, and not a feat of delivery. Writing a product in a real work environment means dealing with other people’s demands and issues. It also means you have to re-think what you do a lot, and that makes for better products. How you built your product does not make it a best practice. It worked for you. OK, but is that repeatable by your audience or can they learn from you approach?

To give a great talk, you need to do a lot of homework:

  • you need to read what the competition did,
  • learn what is applicable,
  • you need to understand how the topic you cover can be beneficial for the audience and
  • you need to do research about the necessary environment of your talk topic and issues people may run into when they try to repeat what you did.

2) Are you sure about your facts?

It is easy to make grandiose statements and wrap them in the right rhetoric to be exciting. It is also easy to cause a lot of trouble with those. If you make a promise on stage, make sure it is yours to fulfill. You don’t want to get your colleagues into trouble or delivery stress by over-promising.

You are likely to present to an audience who know their stuff and are happy to find holes in your argumentation. Therefore you need to do your homework. Check your facts, keep them up-to-date and don’t repeat truisms of the past.

Get the newest information, and verify that it is fact before adding it to your talk. This also means checking various sources and cross-referencing them. Legwork, research.

Work with your colleagues who will need to deliver what you talk about and maintain it in the future. Ensure they are up to the task. Remember: you are not likely to be the maintainer, so delegate. And delegation means you need to give others a heads-up what is coming their way.

3) Are you aware of the audience?

Your job is to educate and entertain the audience of the conference. To achieve this, you need to cater your talk to the audience. Therefore you need to understand them before you go forward. For this, you need to follow some steps:

Get information about the audience from the conference organisers:

  • How big is the audience?
  • When is your talk – a talk at the end of the day is harder to take in than one in the morning.
  • What is their experience level – you write different materials for experts than for novices. Peer pressure dictates that everyone tells you they are experts. They might still not understand what you do unless you explain it well.
  • What is the language of the audience? Are they native speakers of your language or do you need to cater for misunderstandings? Do your pop references and jokes make sense in that country, or are they offensive or confusing? If there is live translation at the event you will have to be slower and pause for the translators to catch up. You will also need to deliver your slides up-front and have a list of technical words that shouldn’t be translated. Your slide deck also needs to be printable for translators to use.

Then think about what you’d like to get out of your talk:

  • Try to think like your audience – what excites a group of designers is not the same a group of developers or project managers need
  • Look at the rest of the line-up. Is your talk unique or will you clash or repeat with another talk at the same event?

4) What’s your story line? How do you package the idea?

A presentation is nothing without a story. Much like a movie you need to have to have an introduction, a climax and a conclusion. Intersperse this with some anectodes and real life comparisons and you have something people can enjoy and learn from. Add some humour and some open questions to engage and encourage. How do you do that? What fits this talk and this audience?

5) Where are the materials you talk about?

If you want the audience to repeat what you talk about you need to make sure your materials are available.

  • Your code examples need to be for example on GitHub, need to work and need documentation.
  • If you talk about a product of your company make sure the resource isn’t going away by the time you give your talk.
  • Your slides should be on the web somewhere as people always ask for them right after your talk.

6) Are you sure you can release the talk the way you wrote it?

It is simple to pretend that we are a cool crowd and everyone gets a good geek joke. It is also easy to offend people and cause a Twitter storm and an ugly aftermath in the tech press.

It is also easy to get into legal trouble for bad-mouthing the competition or using media nilly-willy. Remember one thing: fair use is a myth and not applicable internationally. Any copyrighted material you use in your talk can become a problem. The simplest way to work around that is to only use creative commons licensed materials.

That might mean you don’t use the cool animated GIF of the latest TV show. And that might be a good thing. Do you know if the audience knows about this show and gets your reference? Thinking internationally and questioning your cultural bias can be the difference between inspiring and confusing. Or frustrating. If you talk about great products that aren’t available in the country you present. Don’t write your talk from your perspective. Think what the audience can do with your material and if they can understand it.

7) When are the materials due?

There are quite a few things that affect the time you have to prepare your presentation:

  • Your company might have a policy to have your slides reviewed by legal and marketing. This sounds terrible and smacks of censorship. But it can save your arse. It might also make you aware of things you can hint at that aren’t public knowledge yet.
  • The conference might need your talks upfront. Every conference wants at least an outline and your speaker bio to publish on their web site.
  • Do you have enough time for research, creation and designing your slides before you travel? Can you upload your deck to the web in case your machine breaks down?

8) What does the conference need from you?

Depending on what the conference does for you, they also want you to help them. That can include:

  • some promotion on your social media channels
  • information about your travel and accomodation
  • VISA requirements and signing releases about filming and material distribution rights
  • invoices for expenses you have on their behalf
  • information on your availability for speaker dinners, event parties or other side activities of the main event

This needs time allocated to it. In general you can say a one day conference will mean you’re out for three.

9) How do you get to the event?

Traveling is the biggest unknown in your journey to the stage. All kind of things can go wrong. You want to make sure you book the right flights, hotels and have a base close to the event. All this costs money, and you will find conference organisers and your company try to cut down on cost whenever they can. So be prepared for some inconvenience.

Booking and validating your travel adds and extra two days to your conference planning. Getting to and from your home to the event can be a packed and stressful journey. Try to avoid getting to the event stressed, you need to concentrate on what you are there for. Add two buffer days before and after the event at least.

Booking your own travel is great. You are not at the mercy of people spelling your name wrong or asking you for all kind of information like your passport and date of birth. But it also means you need to pay for it in some way or another and you want that money back. Finding a relaxed and affordable schedule is a big task, and something you shouldn’t take too lightly.

10) Do you have all you need? Is everything going to be fine while you’re gone?

You are going to be out for a while. Both from work and your home. Make sure that in your absence you have people in place that can do the job you normally do. Make sure you covered all the needs like passport and visa issues and you know everything about the place you go to.

Prepare to get sick and have medication with you. It can happen and it should not be the end of the trip. Stay healthy, bring some safe food and plan for time to work out in between sitting cramped on planes and in cars.

Do you know how to get to the hotel and around the city you present in? Do you speak the language? Is it safe? Is there someone to look after your home when you’re gone? Prepare for things going wrong and you having to stay longer. Planes and trains and automobiles fail all the time.

11) Who pays what – how do you get your money back?

Conference participation costs money. You need to pay for travel, accomodation, food, wireless, mobile roaming costs and many more unknowns. Make sure you get as much paid for you as possible. Many conference organisers will tell you that you can pay for things and keep receipts. That means you will have to spend quite some time with paperwork and chasing your money. The same applies to company expense procedures. You need to deal with this as early as possible. The longer you wait, the harder it gets.

12) Can you afford the time? Do you need to extend your trip to make it worth while?

A local event is pretty easy to sell to your company. Flying somewhere else and having the both the cost of money and time involved is harder. Even when the conference organiser pays – it means you are out of the office and not available for your normal duty. One way to add value for your company is to add meetings with local clients and press. These need to be organised and planned. So ensure you cater for that.

13) Have you prepared for a presentation in the conference environment?

It is great to use online editors to write your talk. It means people can access your slides and materials. It also means you are independent of your computer – which can and will behave oddly as soon as you are on stage. Online materials are much less useful once you are offline on stage. Conference wireless is anything but reliable. Make sure you are not dependent on a good connection. Ask about the available resolution of the conference projection equipment. Don’t expect sound to be available. And above all – bring your own connectors and power cables and converters.

14) How do you measure if this was a success?

Your company gave you time and money to go to a conference and give a talk. How do you make this worth their while? You have to show something on your return. Make sure you measure the feedback your talk got. See if you can talk to people at the event your company considers important. Collect all this during the event and analyse and compact it as soon as you can. This sounds simple, but it is tough work to analyse sentiment. A Twitter feed of a conference is pretty noisy.

15) How do you make this re-usable for your company?

If you work for a larger company, they expect of you as an evangelist to make your materials available for others. A lot of companies believe in reusable slide decks – for better or worse. Prepare a deck covering your topic that is highly annotated with delivery notes. Prepare to present this to your company. Whilst hardly anything is reusable, you are expected to make that happen.

16) Are you ready to deal with the follow-up?

After the conference you have to answer emails, contact requests and collect and note down your leads. Most companies expect a conference report of some sort. Many expect you to do some internal presentation to debrief you. What you did costs a lot of time and money and you should be prepared to prove your worth.

You’ll get more requests about your talk, the products you covered and people will ask you to speak at other events. And thus the cycle starts over.


That’s just a few of the things you have to consider as a presenter at conferences. I didn’t deal with stress, jet lag, demands, loneliness and other mental influences here. Next time you claim that people “talk instead of being a real coder” consider if what you’re saying is valid criticism or sounds a bit like “bro, do you even lift?”. Of course there are flim-flam artists and thinly veiled sales people calling themselves evangelists out there. But that doesn’t mean you should consider them the norm.

Will Kahn-GreeneInput: 2015q3 quarter in review

Things to know:

  • Input is Mozilla's product feedback site.
  • Fjord is the code that runs Input.
  • We maintain project details and plans at
  • I am Will Kahn-Greene and I'm the tech lead, architect, QA and primary developer on Input.

This is the quarter in review for Mozilla Input!

Read more… (2 mins to read)

Stuart ColvilleRemoving leading whitespace in ES6 template strings

In some recent code at work we're using fairly large strings for error descriptions.

JavaScript has always made it hard to deal with long strings, especially when you need to format them across multiple lines. The solutions have always been that you need to concatenate multiple strings like so:

var foo = "So here is us, on the " +  
  "raggedy edge. Don't push me, " +
  "and I won't push you.";

Or use line-continuations:

var foo = "So here is us, on the \  
  raggedy edge. Don't push me, \
  and I won't push you.";

Neither of these are pretty. The latter was originally strictly illegal in ECMAScript (hattip Joseanpg):

A 'LineTerminator' character cannot appear in a string literal, even if preceded by a backslash \. The correct way to cause a line terminator character to be part of the string value of a string literal is to use an escape sequence such as \n or \u000A.

There's a rather wonderful bug on bugzilla discussing the ramifications of changing behaviour to strictly enforce the spec back in 2001. In case you're wondering it was WONTFIXED.

In ECMAScript 5th edition this part was revised to the following:

A line terminator character cannot appear in a string literal, except as part of a LineContinuation to produce the empty character sequence. The correct way to cause a line terminator character to be part of the String value of a string literal is to use an escape sequence such as \n or \u000A.

Anyway, enough with the history lesson, we now have features in ES6 on the horizon and if you're already starting to use ES6 via the likes of babel or as features become available then it provides some interesting possibilities.

Diving in with ES6 template strings

Having seen template strings I jumped right in only to find this happening.

var raggedy = 'raggedy';  
console.log(`So here is us, on the  
             ${raggedy} edge. Don't push
             me, and I won't push you.`);

So that looks neat right? But hang-on what does it output?

So here is us, on the  
             raggedy edge. Don't push
             me, and I won't push you.

Dammit - so by default template strings preserve leading whitespace like heredoc in PHP (which is kind of a memory I'd buried).

Ok so reading more on the subject of es6 template strings, processing template strings differently is possible with tag functions. Tags are functions that allow you to process the template string how you want.

Making a template tag

With that in mind I thought OK, I'm going to make a tag to make template strings have no leading whitespace on multiple lines but still handle var interpolation as by default.

Here's the code (es6) (note a simpler version is linked to at the end of this post if you're not using full-fat es6 via babel):

export function singleLineString(strings, ...values) {  
  // Interweave the strings with the
  // substitution vars first.
  let output = '';
  for (let i = 0; i < values.length; i++) {
    output += strings[i] + values[i];
  output += strings[values.length];

  // Split on newlines.
  let lines = output.split(/(?:\r\n|\n|\r)/);

  // Rip out the leading whitespace.
  return => {
    return line.replace(/^\s+/gm, '');
  }).join(' ').trim();

The way tags work is they're passed an array of strings and the rest of the args are the vars to be substituted. Note: as we're using ES6 in this example we've made values into an array by using the spread operator. If the original source string was setup as follows:

var two = 'two';  
var four = 'four';  
var templateString = `one ${two} three ${four}`;  

Then strings is: ["one ", " three ", ""] and values is ["two", "four"]

The loop up front is just dealing with interleaving the two lists to do the var substitution in the correct position.

The next step is to split on newlines to get a list of lines. Then the leading whitespace is removed from each line. Lastly the list is joined with a space between each line and the result is trimmed to remove any trailing space.

The net effect is that you get an easy way to have a long multiline string formatted nicely with no unexpected whitespace.

var raggedy = 'raggedy';  
console.log(singleLineString`So here is us, on the  
            ${raggedy} edge. Don't push
            me, and I won't push you.`);


So here is us, on the raggedy edge. Don't push me, and I won't push you.  

Trying this out in the browser

As template strings are becoming more and more available - here's a version without the fancy ES6 syntax which should work in anything that supports template strings:


All in all it's not too bad. Hopefully someone else will find this useful. Let us know if you have suggestions or alternative solutions.

Air MozillaMozilla Weekly Project Meeting

Mozilla Weekly Project Meeting The Monday Project Meeting

Air MozillaPreview: Rally for the User

Preview: Rally for the User A peek at what's coming in the Rally for the User

Mozilla WebDev CommunityExtravaganza – October 2015

Once a month, web developers from across Mozilla get together to see who can score the highest car emissions rating. While we scour the world for dangerous combustibles, we find time to talk about the work that we’ve shipped, share the libraries we’re working on, meet new folks, and talk about whatever else is on our minds. It’s the Webdev Extravaganza! The meeting is open to the public; you should stop by!

You can check out the wiki page that we use to organize the meeting, or view a recording of the meeting in Air Mozilla. Or just read on for a summary!

Shipping Celebration

The shipping celebration is for anything we finished and deployed in the past month, whether it be a brand new site, an upgrade to an existing one, or even a release of a library.

One and Done on Heroku

First up was bsilverberg with the news that One and Done, Mozilla’s contributor task board, has successfully migrated from the Mozilla-hosted Stackato PAAS to Heroku. One and Done takes advantage of a few interesting features of Heroku, such as App Pipelines and Review Apps.

Pontoon Sync Improvements and New Leaderboards

Next was Osmose (that’s me!) sharing a few new features on Pontoon, a site for submitting translations for Mozilla software:

  • mathjazz added a new “Latest Activity” column to project and locale listings.
  • jotes added time-based filters to the leaderboard as well as several performance improvements to the page.
  • I added inc file support to the new sync process, as well as a few other fixes such that all Pontoon projects are now using the new sync. Yay!

Air Mozilla iTunes Video Podcast

Peterbe stopped by to share the news that Air Mozilla now has an iTunes-compatible podcast feed for all of its videos. The feed has already been approved by Apple and is available on the iTunes Store.

DXR Static File Cachebusting

ErikRose shared the news that DXR now adds hashes to static file filenames so that updates to the static files don’t get messed up by an old local cache. Interestingly, instead of relying on popular tools like Grunt or Webpack, Erik opted to implement the hashing using some logic in a Makefile plus a little bit of Python. You can check out the pull request to see the details of the change.

Replacing localForage with localStorage

Next we went back to Peterbe, who recently replaced localForage, a library that abstracts several different methods of storing data locally in the browser, with localStorage, the blocking, built-in storage solution that ships with browsers. He also shared a blog post that showed that not only is localStorage simpler to use, it was actually faster in his specific use case. Hosted on Deis

Next was jgmize sharing the news that is now hosted on a Deis cluster. Currently a small amount of production data is being hosted by the cluster, but a larger rollout is planned for the near future. Giorgos is responsible for the entire Jenkins setup, including a neat deployment pipeline display, an Ansible playbook, and the deployment pipeline scripts. Pmac ported over hundreds of Apache redirects to Python and wrote a comprehensive set of tests for them as well.


The Roundtable is the home for discussions that don’t fit anywhere else.

Farewell to Wenzel

Lastly, I wanted to specifically call out wenzel, whose last day as a paid contributor for Mozilla was last Friday. Wenzel has been a Mozillian for 9 years, starting as an intern. He’s contributed to almost every major Mozilla web property, and will be missed.

This month’s winner was willkg, with an impressive 200% rating, generating more pollution than the fuel he put in. Local science expert Dr. Potch of Mr. Potch’s Questionable Ethics and Payday Loan Barn was quoted as saying that willkg’s score was “possible”.

If you’re interested in web development at Mozilla, or want to attend next month’s Extravaganza, subscribe to the mailing list to be notified of the next meeting, and maybe send a message introducing yourself. We’d love to meet you!

See you next month!

Yunier José Sosa VázquezLos principios propuestos por Mozilla para el bloqueo de contenido

Esta es una traducción del artículo original publicado en el blog de The Mozilla Blog. Escrito por Denelle Dixon-Thayer.

El bloqueo de contenido se ha convertido en un tema candente en toda la web y en los ecosistemas móviles. Ya se ha estado convirtiendo en algo penetrante en el escritorio, y ahora Apple ha hecho posible el desarrollo de aplicaciones para iOS cuya finalidad es bloquear el contenido. Esto causó la más reciente oleada de actividad, de preocupación y de enfoque. Tenemos que prestar atención.

El bloqueo de contenido no va a desaparecer – ahora es parte de nuestra experiencia en línea. Pero el paisaje no se entiende bien, por lo que es difícil saber la mejor manera de avanzar en un ambiente sano, la Web abierta. Los usuarios quieren que -ya sea para evitar la visualización de anuncios, protección contra el seguimiento no deseado, mejorar la velocidad de carga, o reducir consumo de datos- y tenemos que abordar la forma en cómo la industria debe responder. Queríamos empezar por el hacking en los principios propuestos para el bloqueo de contenido. La creciente disponibilidad y uso de los bloqueadores de contenido nos dice que los usuarios quieren controlar su experiencia.

Ésto es una cosa buena. Pero algunos bloqueadores de contenido podrían ser perjudiciales en formas que pueden no ser evidentes. Por ejemplo, si el bloqueo de contenido crea nuevos porteros que pueden elegir a los ganadores y perdedores en el espacio editorial o que favorezcan sus propios contenidos por encima de otros, que en última instancia, perjudica a la competencia y la innovación. A la larga, los usuarios pueden perder tanto control como el que ganan. Lo mismo sucede si el modelo comercial de la Web no forma parte del debate de bloqueo de contenido.

En mi último artículo, yo transmití nuestra intención de colaborar con este paisaje, no sólo a través del análisis y la investigación, pero también a través de la experimentación, desarrollo de productos, y la promoción.

Para ayudar a guiar nuestros esfuerzos y esperando informar a otros, hemos desarrollado tres propuestas “principios del bloqueo de contenido” que ayudarían a avanzar en los efectos beneficiosos de bloqueo de contenido y reducir al mínimo los riesgos. Queremos de su ayuda en ellos. Así como nuestros principios de privacidad de datos ayudan a guiar nuestras prácticas de datos, estos principios de bloqueo de contenido ayudarán a guiar lo que construimos y lo que apoyamos a través de la industria.

El contenido no es intrínsecamente bueno o malo – con algunas excepciones notables, como el malware. Así que estos principios no son acerca de qué contenido es aceptable para bloquear y cuál no lo es. Ellos hablan de cómo y por qué el contenido puede ser bloqueado, y cómo el usuario se puede mantener en el centro a través de ese proceso.

En Mozilla, nuestra misión es garantizar una web abierta y de confianza, y que pone a nuestros usuarios el control. Para el bloqueo de contenido, esto es lo que pensamos que significa:

  • La neutralidad del contenido: El software de bloqueo de contenido debe centrarse en atender las necesidades de los usuarios potenciales (tales como el rendimiento, la seguridad y la privacidad), en lugar de bloquear determinados tipos de contenidos (como la publicidad).
  • Transparencia y Control: El software de bloqueo de contenido debe proporcionar a los usuarios la transparencia y controles significativos sobre las necesidades que está tratando de resolver.
  • Apertura: El bloqueo debe mantener la igualdad de condiciones y debe bloquear con los mismos criterios independientemente de la fuente del contenido. Los editores y otros proveedores de contenido deberían tener formas de participar en un ecosistema de Web abierta, en lugar de ser colocado en una caja penalizada permanente que cierra la Web para sus productos y servicios.

Díganos lo que piensa de estos principios propuestos en sus canales sociales usando #contentblocking y únete a nosotros el viernes 9 de octubre a las 11 A.M PT. para nuestra #BlockParty, una conversación en torno a los problemas y las posibles soluciones a las cuestiones referentes al bloqueo de contenidos. Esperamos con interés trabajar con nuestros usuarios, nuestros socios y el resto del ecosistema Web para avanzar en nuestro objetivo común de una vida sana de Web abierta.

Fuente: Mozilla Hispano

The Mozilla BlogKatharina Borchert to Join Mozilla Leadership Team as Chief Innovation Officer

We are excited to announce that Katharina Borchert will be transitioning from our Board of Directors to join the Mozilla leadership team as our new Chief Innovation Officer starting in January.

Mozilla was founded and has thrived based upon the principles of open innovation. We bring together thousands of people from around the world to build great products and empower others with technology, know-how and opportunity to advance the open Web. As Mozilla’s new Chief Innovation Officer, Katarina will be broadly responsible for fostering and further enriching Mozilla’s culture of open innovation and driving our process for identifying new opportunities, prioritizing them, and funding focused explorations across the whole of Mozilla’s global community.

Katharina has a background that includes more than a decade of new business growth and technological innovation in media and journalism, most recently as CEO at Spiegel Online, the online division of one of Europe’s most influential magazines. Prior to that, Katharina was Editor-in-Chief and CEO at WAZ Media Group, where she completely reimagined the way local and regional journalism could be done, launching a new portal “Der Westen” based heavily upon user participation, integrated social media, and one of the earliest with a focus on location-based data in journalism.

Most recently at Mozilla she has served on our Board of Directors since early 2014, and we have come to rely upon her keen strategic insights, broad knowledge of the Internet landscape and her significant executive leadership experience. She has become a strategic ally — a true Mozillian, who cares deeply about the issues of privacy, online safety and transparency that are all critical to the future of a healthy Internet and core to our mission.

Our success comes from fostering a true culture of open innovation in the world and our focus on product and technological innovation remains central to the fulfillment of our mission.

The entire Mozilla community welcomes you, Katharina.


John FordSplitting out taskcluster-base into component libraries

The intended audience of this post is people who either work with taskcluster-base now or are interested in implementing taskcluster services in the future.

Taskcluster serverside components are currently built using the suite of libraries in the taskcluster-base npm package. This package is many things: config parsing, data persistence, statistics, json schema validators, pulse publishers, a rest api framework and some other useful tools. Having these all in one single package means that each time a contributor wants to hack on one part of our platform, she'll have to figure out how to install and run all of our dependencies. This is annoying when it's waiting for a library build, but just about impossible for contributors who aren't on the Taskcluster platform team. You need ​Azure, Influx and AWS accounts to be able to run the full test suite. You also might experience confusing errors in a part of the library you're not even touching.

Additionally, we are starting to get to the point where some services must upgrade one part of taskcluster-base without using other parts. This is generally frowned upon, but sometimes we just need to put a bandaid on a broken system that's being turned off soon. We deal with this currently by exporting base.Entity and base.LegacyEntity. I'd much rather we just export a single base.Entity and have people who need to keep using the old Entity library use taskcluster-lib-legacyentity directly

We're working on fixing this! The structure of taskcluster-base is really primed and ready to be split up since it's already a bunch of independent libraries that just so happen to be collocated. The new component loader that landed was the first library to be included in taskcluster-base this way and I converted our configs and stats libraries last week.

The naming convention that we've settled on is that taskcluster libraries will be prefix with taskcluster-lib-X. This means we have taskcluster-lib-config, taskcluster-lib-stats. We'll continue to name services as taskcluster-Y, like taskcluster-auth or taskcluster-confabulator.  The best way to get the current supported set of taskcluster libraries is still going to be to install the taskcluster-base npm module.

Some of our libraries are quiet large and have a lot of history in them. I didn't really want to just create a new repository and copy in the files we care about and destroy the history. Instead, I wrote a simple and ugly tool ( which does the pedestrian tasks involved in this split up by filtering out irrelevant history for each project, moving files around and doing some preliminary cleanup work on the new library.

This tooling gets us 90% of the way to a split out repository, but as always, a human is required to take it the last step of the way. Imports need to be fixed, dependencies must be verified and tests need to be fixed. I'm also taking this opportunity to implement babel-transpiling support in as many libraries as I can. We use babel everywhere in our application code, so it'll be nice to have it available in our platform libraries as well. I'm using the babel-runtime package instead of requiring the direct use of babel. The code produced by our babel setup is tested in tested using the node 0.12 binary without any wrappers at all.

Having different libraries will introduce the risk of our projects having version number hell. We're still going to have a taskcluster-base npm package. This package will simply be a package.json file which specifies the supported versions of the taskcluster-lib-* packages we ship as a release and an index.js file which imports and re-exports the libraries that we provide. If we have two libraries that have codependent changes, we can land new versions in those repositories and use taskcluster-base as the synchronizing mechanism.

A couple of open questions that I'd love to get input on are how we should share package.json snippets and babel configurations. We mostly have a solution for eslint, but we'd love to be able to share as much as possible in our .babelrc configuration files. If you have a good idea for how we can do that, please get in touch!

One of the goals in doing this is to make writing taskcluster components easier to write. We'd love to see components written by other teams use our framework since we know it's tested to work with Taskcluster well. It also makes it easier for the task cluster team to advise on design and maintenance concerns.

Once a few key changes have landed, I will write a series of blog posts explaining how core taskcluster services are structured.

Daniel PocockRTC Quick Start becoming a book, now in beta

The Real-Time Communications (RTC) Quick Start Guide started off as a web site but has recently undergone bookification.

As of today, I'm calling this a beta release, although RTC is a moving target and even when a 1.0 release is confirmed, the book will continue to evolve.

An important aspect of this work is that the book needs to be freely and conveniently available to maximize participation in Free RTC. (This leads to the question of which free license should I choose?)

The intended audience for this book are people familiar with setting up servers and installing packages, IT managers, system administrators and support staff and product managers.

There are other books that already explain things like how to setup Asterisk. The RTC Quick Start Guide takes a more strategic view. While other books discuss low-level details, like how to write individual entries in the Asterisk extensions.conf file, the RTC Quick Start Guide looks at the high level questions about how to create a network of SIP proxies, XMPP servers and Asterisk boxes and how to modularize configuration and distribute it across these different components so it is easier to manage and support.

Some chapters give very clear solutions, such as DNS setup while other chapters present a discussion of issues that are managed differently in each site, such as user and credential storage.

One of the key themes of the book is the balance between Internet architecture and traditional telephony, with specific recommendations about mixing named user accounts with extension numbers.

Many people have tried SIP or XMPP on Linux in the past and either found themselves overwhelmed by all the options in Asterisk (start with a SIP proxy, it is easier) or struggling with NAT issues (this has improved with the introduction of ICE and TURN, explained in a chapter on optimizing connectivity).

The guide also looks at the next generation of RTC solutions based on WebRTC and gives specific suggestions to people deploying it with JSCommunicator.

Help needed

There are many ways people can help with this effort.

The most important thing is for people to try it out. If you follow the steps in the guide, does it help you reach a working solution? Give feedback on the Free RTC mailing list or raise bug reports against any specific packages if they don't work for you.

The DocBook5 source code of the book is is available on Github and people can submit changes as pull requests. There are various areas where help is needed: improvements to the diagrams, extra diagrams and helping add details to the chapter about phones, apps and softphones.

How could the book be made more useful for specific sectors such as ISPs, hosting providers, the higher education sector or other domains that typically lead in the deployment of new technology?

There is a PDF version of the book for download, it has been created using the default templates and stylesheets. How could the appearance be improved? Should I look at options for having it made available in print?

The book is only available in English at the moment, what is the best strategy for supporting translations and engaging with translators?

Are there specific communities or projects that the book should be aligned with, such as The Linux Documentation Project? (Note: RTC is not just for Linux and people use many of these components on BSD-like platforms, Windows, Mac and Android).

Which is the best license to choose to engage contributors and translators and ensure the long term success of the project?

Another great way to help is to create links to the book from other web sites and documents.

Any questions or feedback on these topics would be very welcome through theFree RTC mailing list.

The Mozilla BlogMozilla, GSMA Publish Study on Mobile Opportunity in Emerging Markets

Mozilla has released a new report — — co-authored with the GSMA. Titled “Approaches to local content creation: realising the smartphone opportunity,” our report explores how the right tools, coupled with digital literacy education, can empower mobile-first Web users as content creators and develop a sustainable, inclusive mobile Web.

In emerging markets like India, Bangladesh and Kenya, many individuals access the Web exclusively through smartphones. Indeed, by the end of 2020, there will be 3 billion people using the mobile internet across the developing world.

Teenagers using Webmaker in Dhaka, Bangladesh

Teenagers using Webmaker in Dhaka, Bangladesh

Improved access is heartening, but a dearth of local content in these regions can render the mobile Web irrelevant, leaving users with little reason to engage. This leads to lost opportunities, and a diminished mobile ecosystem.

In this report, Mozilla and the GSMA explore solutions to this challenge. Mozilla and the GSMA sought to answer three key questions:

  • What level of digital literacy is necessary to empower mobile-first users?
  • What kind of tools enable users to easily create content?
  • Can the right training and tools significantly impact the digital ecosystem in mobile-first countries?

Our findings draw on a range of data: 12 weeks of ethnographic research in emerging markets throughout Africa, Asia and the Americas; one year of user-centered design, testing and iteration of Webmaker for Android, Mozilla’s app for spurring local content creation; two pilot studies exploring the relationship between digital skills on mobile Web usage; and additional analysis.

We explored a range of topics — from language to learning to networks — but reached a central conclusion: Higher skill levels and a larger amount of relevant content would benefit a range of actors, including the mobile industry, government and civil society. If the right investments are made, many more newcomers to the internet will enjoy the benefits of online life, and will be able to create value for themselves and others in the process.

Additional lessons learned include:

  • There is a latent appetite to create content in emerging markets. Research participants and user testers were hugely excited and enthusiastic about the idea of creating for the Internet.
  • Sharing is a powerful motivator for original content creation. In some of our testing contexts, we have observed that the social incentives for “sharing” content provide the hook that leads a user to generate his or her own original content.
  • Designing for the “next billion” requires the same focus and respect for the user as designing for those already online. Simply because some are new to the Web, or to content creation, does not mean that those creating platforms and applications should underrate their ability to handle and even enjoy complexity.
  • Users do not want to create the same content as everyone else. During workshops, participants continually broke free of our restrictions, escaping the templates and the grids they were provided with, to experiment with more open-ended and fun concepts.

To read the full report, visit

Mozilla and the GSMA began their partnership in 2014, motivated by the growing number of people coming online through smartphones and the desire to spark local content creation. To read past research findings, visit

This Week In RustThis Week in Rust 100

Hello and welcome to another issue of This Week in Rust! Rust is a systems language pursuing the trifecta: safety, concurrency, and speed. This is a weekly summary of its progress and community. Want something mentioned? Tweet us at @ThisWeekInRust or send us an email! Want to get involved? We love contributions.

This Week in Rust is openly developed on GitHub. If you find any errors in this week's issue, please submit a PR.

This week's edition was edited by: nasa42, brson, and llogiq.

Updates from Rust Community

News & Blog Posts

Notable New Crates & Projects

  • Plumbum. Conduit-like data processing library for Rust.
  • rust-keepass. Crate to use KeePass databases in Rust.
  • Rusoto. AWS client libraries for Rust.
  • fired. Fast init system for Redox OS.
  • Rust Release Explorer.
  • cargo-edit. A utility for adding cargo dependencies from the command line.
  • Rust MetroHash. Rust implementation of MetroHash - a high quality, high performance hash algorithm.
  • rose_tree. An implementation of the rose tree data structure for Rust.
  • daggy. A directed acyclic graph data structure for Rust.
  • hdfs-rs. libhdfs binding and wrapper APIs for Rust.
  • cargo.el. Emacs minor mode for Cargo.

Updates from Rust Core

102 pull requests were merged in the last week.

Notable changes

New Contributors

  • Carlos Liam
  • Chris C Cerami
  • Craig Hills
  • Cristi Cobzarenco
  • Daniel Carral
  • Daniel Keep
  • glendc
  • Joseph Caudle
  • J. Ryan Stinnett
  • Kyle Robinson Young
  • panicbit
  • Yoshito Komatsu

Approved RFCs

Changes to Rust follow the Rust RFC (request for comments) process. These are the RFCs that were approved for implementation this week:

Final Comment Period

Every week the team announces the 'final comment period' for RFCs and key PRs which are reaching a decision. Express your opinions now. This week's FCPs are:

New RFCs

Upcoming Events

If you are running a Rust event please add it to the calendar to get it mentioned here. Email Erick Tryzelaar or Brian Anderson for access.

fn work(on: RustProject) -> Money

No jobs listed for this week. Tweet us at @ThisWeekInRust to get your job offers listed here!

Crate of the Week

The Crate of this week is Conrod, a simple to use intermediate-mode GUI library written in pure Rust. Thanks to 7zf.

Conrod forgos the traditional "wrap the default GUI for each operating system/desktop environment" approach and uses OpenGL to present a simple, but color- as well as powerful GUI in its own style. There are a good number of widgets implemented already, and writing GUI code with conrod is a breeze thanks to the very streamlined interface.

Quote of the Week

War is Unsafe

Freedom is Safety

Ignorance is Type-checked

(The new trifecta for

killercup on /r/rust.

Thanks to ruudva for the tip. Submit your quotes for next week!

Mike ShalLinux Namespacing Pitfalls

Linux namespaces are a powerful feature for running processes with various levels of containerization. While working on adding them to the tup build system, I stumbled through some problems along the way. For a rough primer on getting started with user and filesystem namespaces, along with how they're used for dependency detection in tup, read on!

Chris CooperRelEng & RelOps Weekly Highlights - October 9, 2015

The beginning of October means autumn in the Northern hemisphere. Animals get ready for winter as the leaves change colour, and managers across Mozilla struggle with deliverables for Q4. Maybe we should just investigate that hibernating thing instead.

Modernize infrastructure: Releng, Taskcluster, and A-team sat down a few weeks ago to hash out an updated roadmap for the buildbot-to-taskcluster migration ( As you can see from the document, our nominal goal this quarter is to have 64-bit linux builds *and* tests running side-by-side with the buildbot equivalents, with a stretch goal to actually turn off the buildbot versions entirely. We’re still missing some big pieces to accomplish this, but Morgan and the Taskcluster team are tackling some key elements like hooks and coalescing schedulers over the coming weeks.

Aside from the Taskcluster, the most pressing releng concern is release promotion. Release promotion entails taking an existing set of builds that have already been created and passed QA and “promoting” them to be used as a release candidate. This represents a fundamental shift in how we deliver Firefox to end users, and as such is both very exciting and terrifying at the same time. Much of the team will be working on this in Q4 because it will greatly simplify a future transition of the release process to Taskcluster.

Improve CI pipeline: Vlad and Alin have 10.10.5 tests running on try and are working on greening up tests (

Kim started discussion on dev.planning regarding reducing frequency of linux32 builds and tests!topic/ (Related bug:

Windows tests take a long time, in case you hadn’t noticed. This is largely due to e10s ( which has effectively doubled the number of tests we need to run per-push. We’ve been able to absorb this extra testing on other platforms, but Windows 7 and Windows 8 have been particularly hard hit by the increased demand, often taking more than 24 hours to work through backlog from the try server. While e10s is a product decision and ultimately in the best interest for Firefox, we realize the current situation is terrible in terms of turnaround time for developer changes. Releng will be investigating updating our hardware pool for Windows machines in the new year. In the interim, please be considerate with your try usage, i.e. don’t test on Windows unless you really need to. If you can help fix e10s bugs so to make that the default on beta/release ASAP, that would be awesome.

Release: The big “moment-in-time” release of Firefox 42 approaches. Rail is on the hook for releaseduty for this cycle, and is overseeing beta 5 builds currently.

Operational: Kim increased size of tst-emulator64 spot pool ( so we’ll be able to enable additional Android 4.3 tests on debug once we have when SETA data for them (

Coop (me) spent last week in Romania getting to know our Softvision contractors in person. Everyone was very hospitable and took good care of me. Alin and Vlad took full advantage of the visit to get better insight into how the various releng systems are interconnected. Hopefully this will pay off with them being able to take on more challenging bugs to advance the state of buildduty. Already they’re starting to investigate how they could help contribute to the slave loan tool. Alin and Vlad will also be joining us for Mozlando in December, so look forward to more direct interaction with them there.

See you next week!

Nick CameronMacros

We're currently planning an overhaul of the syntax extension and macro systems in Rust. I thought it would be a good opportunity to cover some background on macros and some of the issues with the current system. (Note, that we're not considering anything really radical for the new systems, but hopefully the improvements will be a little bit more than incremental). In this blog post I'd like to talk a bit about macros in general. In later posts I'll try and cover some more Rust-specific things and some areas (like hygiene) in more detail. If you're a Lisp (or Rust macro) expert, this post will probably be very dull.

What are macros?

Macros are a syntactic programming language feature. A macro use is expanded according to a macro definition. Macros usually look somewhat like functions, however, macro expansion happens entirely at compile-time (never at runtime), and usually in the early stages of compilation - sometimes as a preprocessing step (as in C), sometimes after parsing but before further analysis (as in Rust).

Macro expansion is usually a completely syntactic operation. That is, it operates on the program text (or the AST) without knowledge about the meaning of that text (such as type analysis).

At its simplest, macro expansion is textual substitution. For example (in C):

#define FOO 42
int x = FOO;  

is expanded by the preprocessor to

int x = 42;  

by simply replacing FOO with 42.

Likewise, with arguments, we just substitute the actual arguments into the macro definition, and then the macro into the source:

#define MIN(X, Y)  ((X) < (Y) ? (X) : (Y))
int x = MIN(10, 20);  

expands to

int x = ((10) < (20) ? (10) : (20));  

After expansion, the expanded program is compiled just like a regular program.

What is macro hygiene?

The naive implementation of macros described above can easily go wrong, for example:

static int a = 42;  
#define ADD_A(X)  ((X) + a)

void foo() {  
    int a = 0;
    int x = ADD_A(10);

You might expect x to be 52 at runtime, but it isn't, it is 10. That's because the expansion is:

static int a = 42;

void foo() {  
    int a = 0;
    int x = ((10) + a);

There is nothing special about a, it is just a name, so the usual scoping rules apply and we get the a in scope at the macro use site, not the macro definition site as you might expect.

These kind of unexpected results are because C macros are unhygienic. An hygienic macro system (as in Lisp or Rust) would preserve the scoping of the macro definition, so post-expansion, the a from the macro would still refer to the global a rather than the a in foo.

This is the simplest kind of macro hygiene. Once we get into the complexities of hygiene, it turns out there is no great definition. Hygiene applies to variables declared inside a macro (can they be referenced outside it?) as well as applying in some sense to aspects such as privacy. Implementing hygiene gets complex when macro definitions can include macro uses and further macro definitions. To make things even worse, sometimes perfect hygiene is too strong and you want to be able to bend the rules in a (hopefully) safe way.

How can macros be implemented?

Macros can be implemented as simple textual substitution, by manipulating tokens after lexing, or by manipulating the AST after parsing. Conceptually though we simply replace a macro use with the definition, whether the use and definition are represented by text, tokens, or AST nodes. There are some interesting details about exactly how lexing, parsing, and macro expansion interact. But, the most interesting implementation aspect is the algorithm used to maintain hygiene (which I'll cover in a later post).

How macros are implemented also depends on how macros are defined. The simple examples I gave above just substitute the macro definition for the macro use. macro_rules macros in Rust and syntax-rules macros in Scheme allow for pattern matching of arguments in the macro definition, so different code is substituted for the macro use depending on the arguments.

Depending on how macros are defined will affect how and when macros are lexed and parsed. (C macros are not parsed until substitution is completely finished. Rust macros are lexed into tokens before expansion and parsed afterwards).

Procedural macros

The macros described so far simply replace a macro use with macro definition. The macro expander might manipulate the macro definition (to implement hygiene or pattern matching), but the macro definition does not affect the expansion other than providing input. In a procedural macro system, each macro is defined as a program. When a macro use is encountered, the macro is executed (at compile time still) with the macro arguments as input. The macro use is replaced by the result of execution.

For example (using a made up macro language, which should be understandable to Rust programmers. Note though that Rust procedural macros work nothing like this):

proc_macro! foo(x) {  
    let mut result = String::new();
    for i in 0..10 {

fn main() {  
    let a = "foo!(bar)"; // Hand-waving about string literals.

will expand to

fn main() {  
    let a = "barbarbarbarbarbarbarbarbarbar";

A procedural macro is a generalisation of the syntactic macros described so far. One could imagine implementing a syntactic macro as a procedural macro by returning the text of the syntactic macro after manually substituting the arguments.

John O'DuinnThe “Distributed” book-in-progress: Early Release#1 now available!

My previous post described how O’Reilly does rapid releases, instead of waterfall-model releases, for book publishing. Since then, I’ve been working with the folks at O’Reilly to get the first milestone of my book ready.

As this is the first public deliverable of my first book, I had to learn a bunch of mechanics, asking questions and working through many, many details. Very time consuming, and all new-to-me, hence my recent silence. The level of detailed coordination is quite something – especially when you consider how many *other* books O’Reilly has in progress at the same time.

Book Cover for DistributedOne evening, while in the car to a social event with friends, I looked up the “not-yet-live” page to show to friends in the car – only to discover it was live. Eeeeek! People could now buy the 1st milestone drop of my book. Exciting, and scary, all at the same time. Hopefully, people like it, but what if they don’t? What if I missed an important typo in all the various proof-reading sessions? I barely slept at all that night.

In O’Reilly language, this drop is called “Early Release #1 (ER#1)”. Now that ER#1 is out, and I have learned a bunch about the release mechanics involved, the next milestone drop should be more routine. Which is good, because we’re doing these every month. Oh, and like software: anyone who buys ER#1 will be prompted to update when ER#2 is available later in Oct, and prompted again when ER#3 is available in Nov, and so on.

You can buy the book-in-progress by clicking here, or clicking on the thumbnail of the book cover. And please, do let me know what you think – Is there anything I should add/edit/change? Anything you found worked for you, as a “remotie” or person in a distributed team, which you wish you knew when you were starting? If you were going to setup a distributed team today, what would you like to know before you started?

To make sure that any feedback doesn’t get lost or caught in spam filters, I’ve setup a special email address (feedback at oduinn dot com) although I’ve already been surprised by feedback via twitter and linkedin. Thanks again to everyone for their encouragement, proof-reading help and feedback so far.

Now, it’s time to brew more coffee and get back to typing.


Nathan Froydgecko include file statistics

I was inspired to poke at which files were most heavily #include‘d and which files contributed the most text as a result of their #include‘ing after seeing the simplicity of Libre Office’s script for doing so. I had to rewrite it in Python, as the obvious modifications to the awk script weren’t working, and I had no taste for debugging awk code. I’ve put the script up as a gist:

It’s intended to be run from a newly built objdir on Linux like so:

python .

The ability to pick a subdirectory of interest:

python dom/bindings/

was useful to me when I was testing the script, so I wasn’t groveling through several thousand files at a time.

The output lines are formatted like so:

total_size file_size num_of_includes filename

and are intended to be manipulated further via sort, etc. The script might work on Mac and Windows, but I make no promises.

The results were…interesting, if not especially helpful at suggesting modifications for future work. I won’t show the entirety of the script’s output, but here are the top twenty files by total size included (size of the file on disk multiplied by number of times it appears as a dependency), done by filtering the script’s output through sort -n -k 1 -r | head -n 20 | cut -f 1,4 -d ' ':

332478924 /usr/lib/gcc/x86_64-linux-gnu/4.9/include/avx512fintrin.h
189877260 /home/froydnj/src/gecko-dev.git/js/src/jsapi.h
161543424 /usr/include/c++/4.9/bits/stl_algo.h
141264528 /usr/include/c++/4.9/bits/random.h
113475040 /home/froydnj/src/gecko-dev.git/xpcom/glue/nsTArray.h
105880002 /usr/include/c++/4.9/bits/basic_string.h
92449760 /home/froydnj/src/gecko-dev.git/xpcom/glue/nsISupportsImpl.h
86975736 /usr/include/c++/4.9/bits/random.tcc
76991387 /usr/include/c++/4.9/type_traits
72934768 /home/froydnj/src/gecko-dev.git/mfbt/TypeTraits.h
68956018 /usr/include/c++/4.9/bits/locale_facets.h
68422130 /home/froydnj/src/gecko-dev.git/js/src/jsfriendapi.h
66917730 /usr/include/c++/4.9/limits
66625614 /home/froydnj/src/gecko-dev.git/xpcom/glue/nsCOMPtr.h
66284625 /usr/include/x86_64-linux-gnu/c++/4.9/bits/c++config.h
63730800 /home/froydnj/src/gecko-dev.git/js/public/Value.h
62968512 /usr/include/stdlib.h
57095874 /home/froydnj/src/gecko-dev.git/js/public/HashTable.h
56752164 /home/froydnj/src/gecko-dev.git/mfbt/Attributes.h
56126246 /usr/include/wchar.h

How does avx512fintrin.h get included so much? It turns out <algorithm> drags in a lot of code, despite people usually only needing min, max, or swap. In this case, <algorithm> includes <random> because std::shuffle requires std::uniform_int_distribution from <random>. This include chain is responsible for essentially all of the /usr/include/c++/4.9-related files in the above list.

If you are compiling with SSE2 enabled (as is the default on x86-64 Linux), then<random> includes <x86intrin.h> because <random> contains a SIMD Mersenne Twister implementation. And <x86intrin.h> is a clearinghouse for all sorts of x86 intrinsics, even though all we need is a few typedefs and intrinsics for SSE2 code. Minus points for GCC header cleanliness here.

What about the top twenty files by number of times included (filter the script’s output through sort -n -k 3 -r | head -n 20 | cut -f 3,4 -d ' ')?

2773 /home/froydnj/src/gecko-dev.git/mfbt/Char16.h
2268 /home/froydnj/src/gecko-dev.git/mfbt/Attributes.h
2243 /home/froydnj/src/gecko-dev.git/mfbt/Compiler.h
2234 /home/froydnj/src/gecko-dev.git/mfbt/Types.h
2204 /home/froydnj/src/gecko-dev.git/mfbt/TypeTraits.h
2132 /home/froydnj/src/gecko-dev.git/mfbt/Likely.h
2123 /home/froydnj/src/gecko-dev.git/memory/mozalloc/mozalloc.h
2108 /home/froydnj/src/gecko-dev.git/mfbt/Assertions.h
2079 /home/froydnj/src/gecko-dev.git/mfbt/MacroArgs.h
2002 /home/froydnj/src/gecko-dev.git/xpcom/base/nscore.h
1973 /usr/include/stdc-predef.h
1955 /usr/include/x86_64-linux-gnu/gnu/stubs.h
1955 /usr/include/x86_64-linux-gnu/bits/wordsize.h
1955 /usr/include/x86_64-linux-gnu/sys/cdefs.h
1955 /usr/include/x86_64-linux-gnu/gnu/stubs-64.h
1944 /usr/lib/gcc/x86_64-linux-gnu/4.9/include/stddef.h
1942 /home/froydnj/src/gecko-dev.git/mfbt/Move.h
1941 /usr/include/features.h
1921 /opt/build/froydnj/build-mc/js/src/js-config.h
1918 /usr/lib/gcc/x86_64-linux-gnu/4.9/include/stdint.h

Not a lot of surprises here. A lot of these are basic definitions for C++ and/or Gecko (<stdint.h>, mfbt/Move.h).

There don’t seem to be very many obvious wins, aside from getting GCC to clean up its header files a bit. Getting us to the point where we can use <type_traits> instead of own homegrown mfbt/TypeTraits.h would be a welcome development. Making js/src/jsapi.h less of a mega-header might help some, but brings of a burden of “did I remember to include the correct JS header files”, which probably devolves into people cutting-and-pasting complete lists, which isn’t a win. Splitting up nsISupportsImpl.h seems like it could help a little bit, though with unified compilation, I suspect we’d likely wind up including all the split-up files at once anyway.

QMOFirefox 42 Beta 7 Testday, October 16th

Greetings Mozillians!

We are holding the Firefox 42.0 Beta 7 Testday next Friday, October 16th. The main focus of this event is Control Center feature. As usual, there will be unconfirmed bugs to triage and resolved bugs to verify. :)

Detailed participation instructions are available in this etherpad.

No previous testing experience is required so feel free to join us on the #qa IRC channel and our moderators will make sure you’ve got everything you need to get started.

Hope to see you all on Friday!

Let’s make Firefox better together!

Vladan DjericUpdate from the Content Performance program #2

During Q3, Avi Halachmi, Aaron Klotz and I compared Firefox's scrolling & page-loading performance against other Windows browsers on several popular sites using a low-end HP Pavilion 14t i3-5010u laptop. This post describes our findings.

First, a refresher…

In my previous post from June, I published our initial Q2 findings:

  • bug 1213413, bug 715376 related: Process-per-tab e10s is necessary to prevent heavy activity in a background tab (e.g. loading GMail) from affecting scrolling smoothness in a foreground tab
  • bug 1213425: Firefox scrolling smoothness badly deteriorates when the laptop is in power-saver mode
  • bug 1174899: Aaron Klotz found a 100% CPU usage bug while scrolling a Facebook profile containing many HTML5 videos
  • Scrolling a Twitter feed with YouTube HTML5 videos is jankier in Firefox, but Twitter newsfeed changed to no longer autoplay videos

The June post also outlined other scenarios needing testing which we studied in Q3.

Our more recent discoveries

NOTE: All phase 1 content-perf findings are in meta bug 1213469, and all content perf bugs we have on file are tagged with [content perf]

  • bug 1213434: Chrome navigates a lot faster to from a Google search result page. The difference is particularly noticeable with a cold network cache. Video showing the differences:
  • bug 1199468: Our smooth-scrolling parameters might not be optimal, but this is still being studied (and debated!)
  • We learned that some graphics acceleration configurations actually harm Firefox scrolling performance:
    • bug 1213429: Scrolling a Facebook profile page with D3D9 acceleration (and D2D disabled) is actually worse than scrolling without any gfx acceleration at all (no D3D + no D2D)
    • bug 1213432: Similarly, D3D11 Warp acceleration (without D2D) provides worse scrolling performance than no gfx acceleration at all (no D3D + no D2D)
    • Direct3D 11 and Direct2D acceleration (either D2D 1.0 or 1.1) did not produce better scrolling performance on our reference pages
      • bug 1213440: In particular, on a Yahoo search page with a few image results embedded, scrolling performance and consistency will be worse with D2D 1.1. than D2D 1.0

During our investigations, we also discovered other user-visible issues that did not directly relate to page scrolling & page loading:

  • bug 1213435: Firefox content-process memory usage is significantly worse than Chrome's and is lagging IE as well
  • bug 1172205: Firefox's page-loading tab throbber spins erratically while loading
  • bug 1213438: Scrolling through a Facebook profile triggers additional network requests, but only Firefox repeatedly changes the tab's title from between its real title and “Connecting…”. This is distracting and draws unnecessary attention to any network delays

We tested many more use cases since the previous progress update, but we mostly found Firefox's performance on par or better:

  • Firefox's scrolling performance did not regress on Windows 10 as compared to Windows 8 (for the 3 reference sites: Yahoo, Facebook and Twitter)
  • Most gfx configurations did not hurt Firefox scrolling performance: external monitor connected, DPI scaling enabled, e10s enabled (comparing non-APZ e10s vs non-e10s), accessibility technology enabled, etc
    • In tests with external monitors, we noticed that Firefox consistently chooses the correct refresh rate, unlike other tested browsers
    • Unfortunately, this finding did not generalize to better gfx performance overall on all multi-monitor setups (bug 1189955)
  • We also found page-loading times on Facebook, Twitter, and Yahoo comparable across browsers
  • As an aside, APZC has a noticeably positive impact on scrolling smoothness, but there are issues with checkerboarding and correctness (bug 1178298, so it might be a while before we see APZC riding the trains.

We didn't have time to get as far as we wanted to with content-perf tooling in Q3, but Wander Costa did contribute a prototype of a tool for measuring browser responsiveness during page-loads:

Content Performance in Q4

The Perf team's top priority in Q4 is to verify e10s performance using our many measurement systems and generally help get e10s performance ready for release.

As a result, Avi will be the only developer working on content-perf this quarter. However, Avi will be working on content-perf full-time in Q4 and he has already covered additional ground (including Fennec). He will soon be blogging about additional content-perf findings over at his blog

Mozilla FundraisingRebuilding Mozilla’s donate form using ReactJS

Last year’s fundraising campaign was a success thanks to the team who worked on it. After the campaign ended our team met together to see what worked well and what didn’t go as planned. The engineers who worked on the … Continue reading

Julien VehentSSL/TLS analysis of the Internet's top 1,000,000 websites

microscope.gifIt seems that evaluating different SSL/TLS configurations has become a hobby of mine. After publishing Server Side TLS back in October, my participation in discussions around ciphers preferences, key sizes, elliptic curves security etc...has significantly increased (ironically so, since the initial, naive, goal of "Server Side TLS" was to reduce the amount of discussion on this very topic).

More guides are being written on configuring SSL/TLS server side. One that is quickly gaining traction is Better Crypto, which we discussed quite a bit on the dev-tech-crypto mailing list.

People are often passionate about these discussions (and I am no exception). But one item that keeps coming back, is the will to kill deprecated ciphers as fast as possible, even if that means breaking connectivity for some users. I am absolutely against that, and still believe that it is best to keep backward compatibility to all users, even at the cost of maintaining RC4 or 3DES or 1024 DHE keys in our TLS servers.

update: this blog post was posted almost two years ago, and thankfully we've managed to almost kill RC4 and 1024 DHE keys in the meantime. I still believe that backward compatibility is critical, but I certainly do not want to have to enable RC4 of weak keys ever again :)

One question that came up recently, on dev-tech-crypto, is "can we remove RC4 from Firefox entirely ?". One would think that, since Firefox supports all of these other ciphers (AES, AES-GCM, 3DES, Camellia, ...), surely we can remove RC4 without impacting users. But without numbers, it is not an easy decision to make.

Challenge accepted: I took my cipherscan arsenal for a spin, and decided to scan the Internet.

Scanning methodology

The scanning scripts are on github at The results dataset is here: Uncompressed, the dataset is around 1.2GB, but XZ does an impressive job at compressing that to a 17MB archive.

I use Alexa's list of top 1,000,000 websites as a source. The script called "" scans targets in parallel, with some throttling to limit the numbers of simultaneous scans around 100, and writes the results into the "results" directory. Each target's results are stored in a json file named after the target. Another script named "", walks through the results directory and computes the stats. It's quite basic, really.

It took a little more than 36 hours to run the entire scan. A total of 451,470 websites have been found to have TLS enabled. Out of 1,000,000, that's a 45% ratio.

While not a comprehensive view of the Internet, it carries enough data to estimate the state of SSL/TLS in the real world.

SSL/TLS survey of 451,470 websites from Alexa's top 1 million websites


Cipherscan retrieves all supported ciphers on a target server. The listing below shows which ciphers are typically supported, and which ciphers are only supported by some websites. This last item is the most interesting, as it appears that 1.23% of websites only accept 3DES, and 1.56% of websites only accept RC4. This is important data for developers who are considering dropping support for 3DES and RC4.

Noteworthy: there are two people, out there, who, for whatever reason, decided to only enable Camellia on their sites. To you, Sirs, I raise my glass.

The battery of unusual ciphers, prefixed with a 'z' to be listed at the bottom, is quite impressive. The fact that 28% of websites support DES-CBC-SHA clearly outlines the need for better TLS documentation and education.

Supported Ciphers         Count     Percent
3DES                      422845    93.6596
3DES Only                 5554      1.2302
AES                       411990    91.2552
AES Only                  404       0.0895
CAMELLIA                  170600    37.7877
CAMELLIA Only             2         0.0004
RC4                       403683    89.4152
RC4 Only                  7042      1.5598
z:ADH-DES-CBC-SHA         918       0.2033
z:ADH-SEED-SHA            633       0.1402
z:AECDH-NULL-SHA          3         0.0007
z:DES-CBC-MD5             55824     12.3649
z:DES-CBC-SHA             125630    27.8269
z:DHE-DSS-SEED-SHA        1         0.0002
z:DHE-RSA-SEED-SHA        77930     17.2614
z:ECDHE-RSA-NULL-SHA      3         0.0007
z:EDH-DSS-DES-CBC-SHA     11        0.0024
z:EDH-RSA-DES-CBC-SHA     118684    26.2883
z:EXP-ADH-DES-CBC-SHA     611       0.1353
z:EXP-DES-CBC-SHA         98680     21.8575
z:EXP-EDH-DSS-DES-CBC-SHA 11        0.0024
z:EXP-EDH-RSA-DES-CBC-SHA 87490     19.3789
z:EXP-RC2-CBC-MD5         105780    23.4301
z:IDEA-CBC-MD5            7300      1.6169
z:IDEA-CBC-SHA            53981     11.9567
z:NULL-MD5                379       0.0839
z:NULL-SHA                377       0.0835
z:NULL-SHA256             9         0.002
z:RC2-CBC-MD5             63510     14.0674
z:SEED-SHA                93993     20.8193
Key negotiation

A pleasant surprise, is the percentage of deployment of ECDHE. 21% is not a victory, but an encouraging number for an algorithm that will hopefully replace RSA soon (at least for key negotiation).

DHE, supported since SSLv3, is closed to 60% deployment. We need to bump that number up to 100%, and soon !

Supported Handshakes      Count     Percent
DHE                       267507    59.2524
ECDHE                     97570     21.6116

Perfect Forward Secrecy is all the rage, so evaluating its deployment is most interesting. I am actually triple checking my results to make sure that the percentage below, 75% of websites supporting PFS, is accurate, because it seems so large to me. Even more surprising, is the fact that 61% of tested websites, either prefer, or let the client prefer, a PFS key exchange (DHE or ECDHE) to other ciphers.

As expected, the immense majority, 98%, of DHE keys are 1024 bits. Several reasons to this:

  • In Apache 2.4.6 and before, the DH parameter is always set to 1024 bits and is not user configurable. Future versions of Apache will automatically select a better value for the DH parameter.
  • Java 6, and probably other libraries as well, do not support a DHE key size larger than 1024 bits.

So, while everyone agrees that requiring a RSA modulus of 2048 bits, but using 1024 bits DHE keys, effectively reduces TLS security, there is no solution to this problem right now, other than breaking backward compatibility with old clients.

On ECDHE's side, handshakes almost always use the P-256 curve. Again, this makes sense, since Internet Explorer, Chrome and Firefox only support P256 at the moment. But according to recent research published by DJB & Lange, this might not be the safest choice.

The curve stats below are to take with a grain of salt: Cipherscan uses OpenSSL under the hood, and I am not certain of how OpenSSL elects the curve during the Handshake. This is an area of cipherscan that needs improvement, so don't run away with these numbers just yet.

Supported PFS             Count     Percent  PFS Percent
Support PFS               342725    75.9131
Prefer PFS                279430    61.8934

DH,1024bits               262561    58.1569  98.1511
DH,1539bits               1         0.0002   0.0004
DH,2048bits               3899      0.8636   1.4575
DH,3072bits               2         0.0004   0.0007
DH,3248bits               2         0.0004   0.0007
DH,4096bits               144       0.0319   0.0538
DH,512bits                76        0.0168   0.0284
DH,768bits                825       0.1827   0.3084

ECDH,P-256,256bits        96738     21.4273  99.1473
ECDH,B-163,163bits        37        0.0082   0.0379
ECDH,B-233,233bits        295       0.0653   0.3023
ECDH,B-283,282bits        1         0.0002   0.001
ECDH,B-571,570bits        329       0.0729   0.3372
ECDH,P-224,224bits        4         0.0009   0.0041
ECDH,P-384,384bits        108       0.0239   0.1107
ECDH,P-521,521bits        118       0.0261   0.1209

A few surprises in the Protocol scanning: there is still 18.7% of websites that support SSLv2! Seriously, guys, we've been repeating it for years: SSLv2 is severely broken, don't use it!

I particularly appreciate the 38 websites that only accept SSLv2. Nice job.

Also of interest, is the 2.6% of websites that support TLSv1.2, but not TLSv1.1. This would make sense, if the number of TLSv1.2 websites was actually larger than 2.6%, but it isn't (0.001%). So I can only imagine that, for some reason, websites use TLSv1 and TLSv1.2, but not 1.1.

Update: ''harshreality'', on HN, dug up a changelog in OpenSSL that could explain this behavior:

Changes between 1.0.1a and 1.0.1b 26 Apr 2012

- OpenSSL 1.0.0 sets SSL_OP_ALL to 0x80000FFFL and OpenSSL 1.0.1 and 1.0.1a set SSL_OP_NO_TLSv1_1 to 0x00000400L which would unfortunately mean any application compiled against OpenSSL 1.0.0 headers setting SSL_OP_ALL would also set SSL_OP_NO_TLSv1_1, unintentionally disablng TLS 1.1 also. Fix this by changing the value of SSL_OP_NO_TLSv1_1 to 0x10000000L Any application which was previously compiled against OpenSSL 1.0.1 or 1.0.1a headers and which cares about SSL_OP_NO_TLSv1_1 will need to be recompiled as a result.

Unsurprisingly, however, the immense majority supports SSLv3 and TLSv1. Respectively 99.6% and 98.7%. The small percentage of websites that support TLSv1.1 and 1.2 is worrisome, but not surprising.

Systems administrators are hardly to blame, considering the poor support of recent TLS versions in commercial products. Vendors could definitely use a push, so before you renew your next contract, make sure to add TLSv1.2 to your wishlist.

Supported Protocols       Count     Percent
SSL2                      85447     18.9264
SSL2 Only                 38        0.0084
SSL3                      449864    99.6443
SSL3 Only                 4443      0.9841
TLS1                      446575    98.9158
TLS1 Only                 736       0.163
TLS1.1                    145266    32.1762
TLS1.1 Only               1         0.0002
TLS1.2                    149921    33.2073
TLS1.2 Only               5         0.0011
TLS1.2 but not 1.1        11888     2.6332

What isn't tested

This is not a comprehensive test. RSA key sizes are not evaluated. Nor are TLS extensions, OCSP Stapling support, and a bunch of features that could be interesting to loop at. Maybe next time.

Educate, and be backward compatible

If this little experiment showed something, it is that old ciphers and protocols are far from dead. Sure, you can decide to kill RC4 and 3DES in your client today, but be aware that a small percentage of the internet will be unreachable to you, and your users.

garrison.jpg What can we do about it? Education is key: TLS is a complex subject, and most administrators and website owners don't have the time and knowledge to dig through dozens of mailing lists and blog posts to find the best configuration choices.

It is the primary motivation for documents such as Server Side TLS and Better Crypto. Some of us are working on improving these documents. But we need an army to broadcast the message, teach administrators in conferences, mailing lists and user groups, and push websites owners to apply more secure configuration to their websites.

We could use some help: go out there and teach TLS !

Air MozillaGerman speaking community bi-weekly meeting

German speaking community bi-weekly meeting Zweiwöchentliches Meeting der deutschsprachigen Community / German speaking community bi-weekly meeting

Yunier José Sosa VázquezLa visión de Mozilla para una Web sana y sostenible

Mozilla FoundationEsta es una traducción del artículo original publicado en el blog de The Mozilla Blog. Escrito por Denelle Dixon-Thayer.

No es nada sorprendente que las últimas discusiones en torno al bloqueo de contenido hayan dado lugar a un debate polarizado sobre los usuarios que optan por bloquear el contenido como una manera de controlar su experiencia Web y los intereses comerciales que monetizan al mismo. Esto, inevitablemente, nos conduce a una discusión acerca de cual contenido es bueno, cual contenido es malo, y cual contenido debe ser bloqueado.

En vez de enfocarnos en los síntomas del problema, deberíamos preguntarnos por qué los usuarios han buscado utilizar objetos contundentes, como bloqueadores de contenido, para ayudarlos a navegar sus vidas en línea. Todavía no sabemos la respuesta completa a esta pregunta. Lo que podemos ver es que los motivos difieren entre los usuarios y puede depender del dispositivo que usen (por ejemplo, los usuarios de escritorio quizás se enfocan más sobre la privacidad por sobre el rendimiento que puede ser un beneficio secundario, mientras que el rendimiento y el uso de datos móviles serían prioridad para un usuario de celular). Nosotros, como industria, debemos entender que necesita el usuario.

Las necesidades del usuario y los intereses comerciales no son un juego de suma cero – las dos son partes complementarias de una próspera web resistente. La creación de un equilibrio entre los beneficios comerciales y los beneficios de los usuarios es de crítica importancia para la salud de la Web.

Una cuestión que requiere más equilibrio son los datos del usuario. La recopilación y el uso de los datos no es inherentemente dañina. La misma ayuda con la alimentación de características personalizadas, la manutención de productos al día, proporcionando soporte al usuario y mejorando la manera en que los mismos trabajan. Darle valor al usuario a través de la recopilación de datos es una forma saludable y necesaria para ayudar a crear experiencias que resulten atractivas para este. Sin embargo, cuando los datos del usuario son recolectados sin darles un valor o control, el intercambio entre el usuario y la industria se vuelve opaco, por lo que la confusión se establece. Es entonces cuando los usuarios empiezan a desconfiar del sistema entero —incluyendo también a los que hacen valer la relación que tienen para con ellos.

Nosotros estamos tratando de llegar a la raíz del problema —pero no solo a través de la investigación. Estamos trabajando también para desarrollar productos, características y el compromiso de apoyar al usuario para que tenga una gran experiencia sin perderse de vista la sostenibilidad comercial.

Necesitamos tu ayuda para encontrar este delicado equilibrio y trazar un camino para una Web basada en la confianza. Adicionalmente, herramientas como LightbeamSmart On Privacy y Web Literacy, son programas que educan a los usuarios y ofrecen un conocimiento de cómo funciona la Web internamente.

En el extremo comercial de la ecuación, estamos jugando un papel de liderazgo (EN) en iniciativas editoriales para que uno se haga cargo de las experiencias entregadas en sus sitios y para ofrecer una experiencia de publicidad más aceptable para los usuarios.

Como industria tenemos que mantener al usuario como centro de la visión de los productos en lugar de ver al mismo sólo como un objeto a adquirir. Esta es la única manera de honrar la elección del usuario y de entregarle la mejor  y más confiable experiencia posible.

Fuente: Mozilla Hispano

Mozilla Open Policy & Advocacy Blog4 Days in NYC for the Open Web Fellows

The inaugural cohort of the Ford-Mozilla Open Web Fellows met in New York last week for only the second time face to face.  Working remotely from Lima, Washington DC, Boston and London, the 6 fellows meet weekly with Melissa Romaine from Mozilla’s San Francisco office, and with me from my home office in Victoria, British Columbia. This was an In Real Life™ meeting we were all looking forward to, if for nothing else than the important reminder that we aren’t squares on a video conference call – we are talented and complicated humans.

Mozilla NYC

The six fellows are placed within Internet Freedom organizations, working on a mixture of team and individual projects.

      • Paola Villarreal, American Civil Liberties Union, Massachusetts.
        Paola is working on Data for Justice, a data-driven advocacy tool that visualizes information critical for eliminating injustice in communities.
      • Tim Sammut, Amnesty International. Tim’s projects are:
        Secure Communications Framework: An approachable framework for human rights researchers that helps them understand how to communicate with contacts around the world safely in the context of varying threats and information sensitivity.
        Community Incident Response: Help human rights organizations in Amnesty’s worldwide network access technical assistance during active digital attacks.
      • Andrea Del Rio, Association for Progressive Communications
        Andrea is creating the web version of the Feminist Principles of The Internet, which aims to inspire people not only to imagine a Feminist Internet but actually build one that is fair, inclusive, empowering and safe for everyone.
      • Drew Wilson, Free Press
        Drew is embedded in Free Press’ Internet2016 campaign and is building tools that internet rights advocates can use to bootstrap their own activism projects.
      • Gem Barrett, Open Technology Institute
        Gem is a member of the MLab team at OTI, helping to build the largest collection of open Internet performance data on the planet.
      • Tennyson Holloway, Public Knowledge
        Tennyson is working on projects that inspire and educate future web advocates. “What can i do for the” is a website that represents a vision of a story based platform that educates, inspires, and assists users to join the open web movement. His other projects involve creating web games that explain tech policy Washington issues, such as copyright and patent trolls.

The Weather Report

Being the first cohort, the 2015 fellows have their fair share of challenges and opportunities.  The challenge: we’re living a plan that is being executed for the first time.  Almost everything needs to be answered by “I don’t know. Let me get back to you”.  On the plus side, this cohort will likely play the largest role in shaping the program and will have the highest degree of input on where we need to make adjustments.  This day was about navigating that tension and also identifying where we are starting to win.


A random sample of substantive issues we discussed:

-How do we design a fellowship program that serves both established and emerging careers?

-What’s the right balance of individual projects and independent research within a fellowship year?

-How do we identify our mentors? Can these people be found for us, or is it in fact something we need to find time to do? (spoiler alert – that’s on us)

Some key takeaways for the Mozilla program team:

-The Mozilla network is a key asset. We need to present the “menu” of potential contacts and access to people that we can provide

-We need to find a way to bring the work of the fellows to Mozilla audiences

-We can assist fellows in finding mentors – those individuals that fellows can go to for advice and that have their best interests at heart

We ended the day with a Q & A with Mozilla’s Executive Director, Mark Surman.  Mark shared with the fellows his vision for leadership development at Mozilla, which he’s previously blogged about here.   He left with two invitations for the cohort – be demanding, and make sure Mozilla is doing all it can to advance your goals.  But also, be generous – give to each other and the program.

Mapping Collaboration

The 2015 cohort is impressive.  They’ve advised governments, settled refugees, built movements and shipped products.  One thing we needed to accomplish together was an identification of the believable ways that the cohort could collaborate together – from running workshops with one another to building a shared project, we spent time mapping this landscape and committing to some next steps. We were joined by Mozilla’s Internet Policy manager Jochai Ben-Avie,who will be working with the cohort during their fellowship year.


Some things we committed to producing together

-5 Lightning Talks we’ll give within the cohort about skills we want to share or an issue we are passionate about

-A Mozilla Wiki page about the fellowship cohort – You can now refer to this page to stay up to date on the 2015 cohort.

-Collaborating with the larger Mozilla Advocacy team to help develop advocacy campaigns

-Net Posi, a podcast about activism started by the cohort – listen to the first episode below and subscribe here.

We headed to midtown for a meeting with Jenny Toomey, Lori McGlinchey and Michael Brennan from Ford’s Internet Rights program.  We were also joined by Joshua Cinelli, who manages Ford’s strategic communications. It was a great chance for us all to learn more about why Internet Rights has been a strategic focus for Ford, and how they see field building and talent development fitting into their strategy.  As Lori McGlinchey, the Internet Rights Program officer expressed – “we need civil society orgs to see technologists not as the cherry on top of a cake they already are having trouble paying for – technologists need to be thought of as essential to these teams”.  It was also a chance for Ford to internalize the diversity and talent of our cohort and the projects we’ve undertaken.  This was the first time that the fellows and Ford staff had met, and we all left with a heightened understanding of not only our role within the Internet Freedom ecosystem, but the opportunities for us to make an impact.


From there we headed to Civic Hall for our closing event.  We hosted 30 activists and technologists for social change in a conversation designed to learn more about the projects of our cohort. We also met with several organizations hoping to place fellows within their organizations in 2016, and were fortunate to be able to dedicate some 1-1 time to these allies in the field.  We split into small groups where fellows lead discussions around their projects.

We finished the evening by braving the rainy ripple effects of Hurricane Joaquin to have a final meal together.  Exhausted but productive, the trains, planes and automobiles took us out of New York to reflect on, internalize, and act on what we’d learned.

A HUGE thank you to Misty Avila who joined us from Aspiration Technology to facilitate our days together.  We couldn’t have accomplished so much without her talent and spirit!


Niko MatsakisVirtual Structs Part 4: Extended Enums And Thin Traits

So, aturon wrote this interesting post on an alternative virtual structs approach, and, more-or-less since he wrote it, I’ve been wanting to write up my thoughts. I finally got them down.

Before I go any further, a note on terminology. I will refer to Aaron’s proposal as the Thin Traits proposal, and my own previous proposal as the Extended Enums proposal. Very good.

(OK, I lied, one more note: starting with this post, I’ve decided to disable comments on this blog. There are just too many forums to keep up with! So if you want to discuss this post, I’d recommend doing so on this Rust internals thread.)


Let me lead with my conclusion: while I still want the Extended Enums proposal, I lean towards implementing the Thin Traits proposal now, and returning to something like Extended Enums afterwards (or at some later time). My reasoning is that the Thin Traits proposal can be seen as a design pattern lying latent in the Extended Enums proposal. Basically, once we implement specialization, which I want for a wide variety of reasons, we almost get Thin Traits for free. And the Thin Traits pattern is useful enough that it’s worth taking that extra step.

Now, since the Thin Traits and Extended Enums proposal appear to be alternatives, you may wonder why I would think there is value in potentially implementing both. The way I see it, they target different things. Thin Traits gives you a way to very precisely fashion something that acts like a C++ or Java class. This means you get thin pointers, inherited fields and behavior, and you even get open extensibility (but, note, you thus do not get downcasting).

Extended Enums, in contrast, is targeting the fixed domain use case, where you have a defined set of possibilities. This is what we use enums for today, but (for the reasons I outlined before) there are various places that we could improve, and that was what the extended enums proposal was all about. One advantage of targeting the fixed domain use case is that you get additional power, such as the ability to do match statements, or to use inheritance when implementing any trait at all (more details on this last point below).

To put it another way: with Thin Traits, you write virtual methods whereas with Extensible Enums, you write match statements – and I think match statements are far more common in Rust today.

Still, Thin Traits will be a very good fit for various use cases. They are a good fit for Servo, for example, where they can be put to use modeling the DOM. The extensibility here is probably a plus, if not a hard requirement, because it means Servo can spread the DOM across multiple crates. Another place that they might (maybe?) be useful is if we want to have a stable interface to the AST someday (though for that I think I would favor something like RFC 757).

But I think there a bunch of use cases for extensible enums that thin traits don’t cover at all. For example, I don’t see us using thin traits in the compiler very much, nor do I see much of a role for them in LALRPOP, etc. In all these cases, the open-ended extensibility of Thin Traits is not needed and being able to exhaustively match is key. Refinement types would also be very welcome.

Which brings me to my final thought. The Extended Enums proposal, while useful, was not perfect. It had some rough spots we were not happy with (which I’ll discuss later on). Deferring the proposal gives us time to find new solutions to those aspects. Often I find that when I revisit a troublesome feature after letting it sit for some time, I find that either (1) the problem I thought there was no longer bothers me or (2) the feature isn’t that important anyway or (3) there is now a solution that was either previously not possible or which just never occurred to me.

OK, so, with that conclusion out of the way, the post continues by examining some of the rough spots in the Extended Enums proposal, and then looking at how we can address those by taking an approach like the one described in Thin Traits.

Thesis: Extended Enums

Let’s start by reviewing a bit of the Extended Enums proposal. Extended Enums, as you may recall, proposed making types for each of the enum variants, and allowing them to be structured in a hierarchy. It also proposed permitting enums to be declared as unsized, which meant that the size of the enum type varies depending on what variant a particular instance is.

In that proposal, I used a syntax where enums could have a list of common fields declared in the body of the enum:

enum TypeData<'tcx> {
    // Common fields:
    id: u32,
    flags: u32,

    // Variants:
    Int { },
    Uint { },
    Ref { referent_ty: Ty<'tcx> },

One could also declare the variants out of line, as in this example:

unsized enum Node {
  position: Rectangle, // <-- common fields, but no variants

enum Element: Node {

struct TextElement: Element {


Note that in this model, the variants, or leaf nodes in the type hierarchy, are always structs. The inner nodes of the hierarchy (those with children) are enums.

In order to support the abstraction of constructors, the proposal includes a special associated type that lets you pull out a struct containing the common fields from an enum. For example, Node::struct would correspond to a struct like

struct NodeFields {
    position: Rectangle,

Complications with common fields

The original post glossed over certain complications that arise around common fields. Let me outline some of those complications. To start, the associated struct type has always been a bit odd. It’s just an unusual bit of syntax, for one thing. But also, the fact that this struct is not declared by the user raises some thorny questions. For example, are the fields declared as public or private? Can we implement traits for this associated struct type? And so forth.

There are similar questions raised about the common fields in the enum itself. In a struct, fields are private by default, and must be declared as public (even if the struct is public):

pub struct Foo { // the struct is public...
   f: i32        // ...but its fields are private.

But in an enum, variants (and their fields) are public if the enum is public:

pub enum Foo { // the enum is public...
    Variant1 { f: i32 }, // ...and so are its variants, and their fields.

This default matches how enums and structs are typically used: public structs are used to form abstraction barriers, and public enums are exposed in order to allow the outside world to match against the various cases. (We used to make the fields of public structs be public as well, but we found that in practice the overwhelming majority were just declared as private.)

However, these defaults are somewhat problematic for common fields. For example, let’s look at that DOM example again:

unsized pub enum Node {
  position: Rectangle,

This field is declared in an enum, and that enum is public. So should the field position be public or private? I would argue that this enum is more struct-like in its usage pattern, and the default should be private. We could arrive at this by adjusting the defaults based on whether the enum declares its variant inline or out of line. I expect this would actually match pretty well with actual usage, but you can see that this is a somewhat subtle rule.

Antithesis: Thin Traits

Now let me pivot for a bit and discuss the Thin Traits proposal. In particular, let’s revisit the DOM hierarchy that we saw before (Node, Element, etc), and see how that gets modeled. In the thin traits proposal, every logical class consists of two types. The first is a struct that defines its common fields and the second is a trait that defines any virtual methods. So, the root of a DOM might be a Node type, modeled like so:

struct NodeFields {
    id: u32

trait Node: NodeFields {
    fn something(&self);
    fn something_else(&self);

The struct NodeFields here just represents the set of fields that all nodes must have. Because it is declared as a superbound of Node, that means that any type which implements Node must have NodeFields as a prefix. As a result, if we have a &Node object, we can access the fields from NodeFields at no overhead, even without knowing the precise type of the implementor.

(Furthermore, because Node was declared as a thin trait, a &Node pointer can be a thin pointer, and not a fat pointer. This does mean that Node can only be implemented for local types. Note though that you could use this same pattern without declaring Node as a thin trait and it would still work, it’s just that &Node references would be fat pointers.)

The Node trait shown had two virtual methods, something() and something_else(). Using specialization, we can provide a default impl that lets us give some default behavior there, but also allows subclasses to override that behavior:

partial impl<T:Node> Node for T {
    fn something(&self) {
        // Here something_else() is not defined, so it is "pure virtual"

Finally, if we have some methods that we would like to dispatch statically on Node, we can do that by using an inherent method:

impl Node {
    fn get_id(&self) -> u32 { }

This impl looks similar to the partial impl above, but in fact it is not an impl of the trait Node, but rather adding inherent methods that apply to Node objects. So if we call node.get_id() it doesn’t go through any virtual dispatch at all.

You can continue this pattern to create subclasses. So adding an Element subclass might look like:

struct ElementFields: NodeFields {

trait Element: Node + ElementFields {

and so forth.

Synthesis: Extended Enums as a superset of Thin Traits

The Thin Traits proposal addresses common fields by creating explicit structs, like NodeFields, that serve as containers for the common fields, and by adding struct inheritance. This is an alternative to the special Node::struct we used in the Extended Enums proposal. There are pros and cons to using struct inheritance over Node::struct. On the pro side, struct inheritance sidesteps the various questions about privacy, visibility, and so forth that arose with Node::struct. On the con side, using structs requires a kind of parallel hierarchy, which is something we were initially trying to avoid. A final advantage for using struct inheritance is that it is a reusable mechanism. That is, whereas adding common fields to enums only affects enums, using struct inheritance allows us to add common fields to enums, traits, and other structs. Considering all of these things, it seems like struct inheritance is a better choice.

If we were to convert the DOM example to use struct inheritance, it would mean that an enum may inherit from a struct, in which case it gets the fields of that struct. For out-of-line enum declarations, then, we can simply create an enum with an empty body:

struct NodeFields {
  position: Rectangle, // <-- common fields, but no variants

enum Node: NodeFields;

struct ElementFields: NodeFields {

enum Element: Node + ElementFields;

(I’ve also taken the liberty of changing from the unsized keyword to an annotation, #[repr(unsized)]. Given that making an enum unsized doesn’t really affect its semantics, just the memory layout, using a #[repr] attribute seems like a good choice. It was something we considered before; I’m not really sure why we rejected it anymore.)

Method dispatch

My post did not cover how virtual method dispatch was going to work. Aaron gave a quick summary in the Thin Trait proposal. I will give an even quicker one here. It was a goal of the proposal that one should be able to use inheritance to refine the behavior over the type hierarchy. That is, one should be able to write a set of impls like the following:

impl<T> MyTrait for Option<T> {
    default fn method1() { ... }
    default fn method2() { ... }
    default fn method3();

impl<T> MyTrait for Option::Some<T> {
    fn method1() { /* overrides the version above */ }
    fn method3() { /* must be implemented */ }

impl<T> MyTrait for Option::None<T> {
    fn method2() { /* overrides the version above */ }
    fn method3() { /* must be implemented */ }

This still seems like a very nice feature to me. As the Thin Traits proposal showed, specialization makes this kind of refinement possible, but it requires a variety of different impls. The example above, however, didn’t have quite so many impls – why is that?

What we had envisioned to bridge the gap was that we would use a kind of implicit sugar. That is, the impl for Option<T> would effectively be expanded to two impls. One of them, the partial impl, provides the defaults for the variants, and other, a concrete impl, effectively implements the virtual dispatch, by matching and dispatching to the appropriate variant:

// As originally envisioned, `impl<T> MyTrait for Option<T>`
// would be sugar for the following two impls:

partial impl<T> MyTrait for Option<T> {
    default fn method1() { ... }
    default fn method2() { ... }
    default fn method3();

impl<T> MyTrait for Option<T> {
    fn method1(&self) {
        match self {
            this @ &Some(..) => Option::Some::method1(this),
            this @ &None => Option::None::method1(this),
    ... // as above, but for the other methods

Similar expansions are needed for inherent impls. You may be wondering why it is that we expand the one impl (for Option<T>) into two impls in the first place. Each plays a distinct role:

  • The partial impl handles the defaults part of the picture. That is, it supplies default impls for the various methods that impls for Some and None can reuse (or override).
  • The impl itself handles the virtual dispatch part of things. We want to ensure that when we call method1() on a variable o of type Option<T>, we invoke the appropriate method1 depending on what variant o actually is at runtime. We do this by matching on o and then delegating to the proper place. If you think about it, this is roughly equivalent to loading a function pointer out of a vtable and dispatching through that, though the performance characteristics are interesting (in a way, it resembles a fully expanded builtin PIC).

Overall, this kind of expansion is a bit subtle. It’d be nice to have a model that did not require it. In fact, in an earlier design, we DID avoid it. We did so by introducing a new shorthand, called match impl. This would basically create the downcasting impl that we added implicitly above. This would make the correct pattern as follows:

partial impl<T> MyTrait for Option<T> { // <-- this is now partial
    default fn method1() { ... }
    default fn method2() { ... }
    default fn method3();

match impl<T> MyTrait for Option<T>; // <-- this is new

impl<T> MyTrait for Option::Some<T> {
    fn method1() { /* overrides the version above */ }
    fn method3() { /* must be implemented */ }

impl<T> MyTrait for Option::None<T> {
    fn method2() { /* overrides the version above */ }
    fn method3() { /* must be implemented */ }

At first glance, this bears a strong resemblance to how the Thin Trait proposal handled virtual dispatch. In the Thin Trait proposal, we have a partial impl as well, and then concrete impls that override the details. However, there is no match impl in Thin Trait proposal. It is not needed because, in that proposal, we were implementing the Node trait for the Node type – and in fact the compiler supplies that impl automatically, as part of the object safety notion.

Expression problem, I know thee well—a serviceable villain

But there is another difference between the two examples, and it’s important. In this code I am showing above, there is in fact no connection between MyTrait and Option. That is, under the Extended Enums proposal, I can implement foreign traits and use inheritance to refine the behavior depending on what variant I have. The Thin Traits pattern, however, only works for implementing the main traits (e.g., Node, Element, etc) – and the reason why is because you can’t write match impls under the Thin Traits proposal, since the set of types is open-ended. (Instead we lean on the compiler-generated virtual impl of Node for Node, etc.)

What you can do in the Thin Traits proposal is to add methods to the main traits and just delegate to those. So I could do something like:

trait MyTrait {
    fn my_method(&self);


trait Node {
    fn my_trait_my_method(&self);

impl MyTrait for Node {
    fn my_method(&self) {
        // delegate to the method in the `Node` trait

Now you can use inheritance to refine the behavior of my_trait_my_method if you like. But note that this only works if the MyTrait type is in the same crate as Node or some ancestor crate.

The reason for this split is precisely the open-ended nature of the Thin Trait pattern. Or, to give this another name, it is the famous expression problem. With Extensible Enums, we enumerated all the cases, so that means that other, downstream crates, can now implement traits against those cases. We’ve fixed the set of cases, but we can extended infinitely the set of operations. In contrast, with Thin Traits, we enumerated the operations (as the contents of the master traits), but we allow downstream crates to implement new cases for those operations.

So method dispatch proves to be pretty interesting:

  • It gives further evidence that Extensible Enums represent a useful entity in their own right.
  • It seems like a case where we may find that the tradeoffs change over time. That is, maybe match impl is not such a bad solution after all, particularly if the Thin Trait pattern is covering some share of the object-like use cases. In which case one of the main bits of magic in the Extensible Enums proposal goes away.


Oh, wait, I already gave it. Well, the most salient points are:

  • Extensible Enums are about a fixed set of cases, open-ended set of operations. Thin Traits are not. This matters.
  • Thin Traits are (almost) a latent pattern in the Extensible Enums proposal, requiring only #[repr(thin)] and struct inheritance.
    • Struct inheritance might be nicer than associated structs anyway.
  • We could consider doing both, and if so, it would probably make sense to implement Specialization, then Thin Traits, and only then consider Extensible Enums.

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Andreas TolfsenThe case against visibility checks in WebDriver

The WebDriver specification came to life as a blueprint description of Selenium’s behaviour to turn what is the de facto browser automation solution, into a specification that would become a de jure standard. Along the way we have rectified and corrected quirks and oddities in the existing work to make commands cohesive units that form part of a larger, more consistent protocol.

Now that almost all of the formal remote end steps are defined, we are looking closer at the relationship among different commands. A part of this is questioning the command primitives, and a current burning issue is the approximation to visibility.

For looking up and interacting with elements, a series of precondition steps must be met, one of which is that the element is deemed visible. The visibility of an element is said to be guided by what is “perceptually visible to the human eye”. This is a tough mark to hit since other web standards we rely on are refusing to go anywhere near this topic. Defining what it means to be visible to the user, it turns out, is extremely difficult to give an exhaustive definition of.

Tree traversal and relationships

From Selenium the specification has inherited a long and complex algorithm to give a crude approximation about the element’s nature and its relationships in the tree. This was further developed to take into account more things that we knew Selenium was missing.

The specification gives a highly non-normative summary of what it means by element visibility:

An element is in general to be considered visible if any part of it is drawn on the canvas within the [boundaries] of the viewport.

Through the special meaning of many HTML features and how the ancestral relationship between different elements have effect on elements’ visibility, it goes on to describe the steps of an algorithm that traverses the tree up and down, starting from the element it is trying to determine the visibility of.

Practically it looks at certain computed (resolved) styling properties that are generally known to make an element invisible, such as display: none, width and height &c. The visibility of certain elements, such as an <option> element, depend upon the characteristics of its parent: For these it traverses up the document until it finds the containing <select> element, then applies the same checks there.

Because many HTML elements need special treatment, each has separate rules defined for them. Some of these rules include <map>, <area>, textual nodes, <img>, but also many more.

Following explicit hiding rules, if the element has more than a single direct descendant element its own visibility will depend upon the visibility of its children. The same is true if any of its direct ancestral elements in tree order fail the visibility test, in which case the visibility will cascade or trickle down to all child elements.

What we arrive at is a recursive algorithm that, although extremely ineffective, tells if a node is visible within the constraints of the tree it is part of. But looking solely at the part of the tree an element is in, overlapping elements from other trees are not considered.

The tree-traversal approach also entirely avoids addressing issues around absolute positioning, custom elements, overflow, and device concepts such as initial- and actual viewport. Owing to some of the provisions it makes around how border widths influence a parent element’s effectual dimensions, or preconceived ideas on how input widgets are styled by user agents, it furthermore ascribes meaning, or interpretation, to areas where the web platform is bad at exposing the primitives.


A suggested alternative to tree traversal is a form of hit-testing that involves testing which element is under the cursor, and then do this for each coordinate of the element’s bounding box that is inside the viewport. This has the upside of avoiding the problems associated with tree traversal altogether, but the downside of being extremely inefficient, and can in the worst scenario be as bad as O(n).

It is also complicated by the fact is that the element inside the bounding box does not necessarily fill the entire rectangle. This is true if the element is clipped by border-radius, has a degree of rotation, or similar. The primitives offered to us give little guidance for tracking the exact path of an element’s shape.

SVG, canvas, Shadow DOM, and transforms

The tree traversal algorithm is also limited to HTML. Other document types such as SVG and canvas have entirely different visibility primitives, and the idea of implicit ancestor visibility simply makes no sense in these contexts.

Shadow DOM is similarly problematic because it introduces the concept of multiple DOMs. Elements that have a Shadow DOM attached do not expose the same standard DOM traversal and query APIs (such as Node, ParentNode, Element) as regular elements.

They also have the idea of scoped stylesheets, whereby it’s possible to style implementation details with a <style> element that just applies to the local scope. Matching rules are also constrained to the same DOM, meaning style selectors in the host document do not match inside a Shadow DOM.

CSS Transforms in itself isn’t an issue, but since the tree traversal algorithm is not a single atomic action, it does not take into account that the state of the document may change whilst it is executing. It should be possible to work around this issue by evaluating the entire algorithm on a sandboxed snapshot of the tree, but again, this exposes us to non-standardised realms of the web platform.


By this point it should almost go without saying that providing a consistent, future-proof method of ascertaining visibility is futile. Whilst WebDriver does have access to the browser internals required to solve this problem, the solution likely lies outside the scope of specifying a remote control protocol.

As we cannot guarantee that new platform features will be taken into account, the tree-traversal approach offered by Selenium is not a building block for the future. It’s a hacky approach that may work reasonably well given the naïve narritive of the simple and undynamic web document world of 10 years ago.

To provide a future-proof notion of naked-eye visibility, there’s a need to push for separate, foundational platform APIs that other standards, in turn, must relate to. WebDriver’s primary role is exposing a privileged remote control interface that enables introspection and control of user agents; not to define element- or textual visibility. When such primitives are made available WebDriver should be an obvious consumer of these.

The good news is that the current Selenium behaviour, given the set of restrictions pointed out, is possible to replicate using existing, public APIs. This will allow consumers to inject automation atoms (chunks of browser-independent JavaScript implementations) to reproduce the behaviour using WebDriver primitives.

The Mozilla BlogProposed Principles for Content Blocking

Content blocking has become a hot issue across the Web and mobile ecosystems. It was already becoming pervasive on desktop, and now Apple’s iOS has made it possible to develop iOS applications whose purpose is to block content. This caused the most recent flurry of activity, concern and focus. We need to pay attention.

Content blocking is not going away – it is now part of our online experience. But the landscape isn’t well understood, making it harder to know how best to advance a healthy, open Web. Users want it –whether to avoid the display of ads, protect against unwanted tracking, improve load speed, or reduce data consumption– and we need to address how we as an industry should respond. We wanted to start by hacking on proposed principles for content blocking. The growing availability and use of content blockers tells us that users want to control their experience.

This is a good thing. But some content blocking could be harmful in ways that may not be obvious. For example, if content blocking creates new gatekeepers who can pick winners and losers in the publishing space or who favor their own content over others’, it ultimately harms competition and innovation. In the long run, users could lose as much control as they gain. The same happens if the commercial model of the Web is not part of the content blocking debate.

In my last post, I conveyed our intention to engage with this landscape, not solely through analysis and research, but also through experimentation, product development, and advocacy.

To help guide our efforts and hopefully inform others, we’ve developed three proposed “content blocking principles” that would help advance the beneficial effects of content blocking while minimizing the risks. We want your help hacking on them. Just as our data privacy principles help guide our data practices, these content blocking principles will help guide what we build and what we support across the industry.

Content is not inherently good or bad – with some notable exceptions, such as malware. So these principles aren’t about what content is OK to block and what isn’t. They speak to how and why content can be blocked, and how the user can be maintained at the center through that process.

At Mozilla, our mission is to ensure a Web that is open and trusted and that puts our users in control. For content blocking, here is what we think that means:

  • Content Neutrality: Content blocking software should focus on addressing potential  user needs  (such as on performance, security, and privacy) instead of blocking specific types of content (such as advertising).
  • Transparency & Control: The content blocking software should provide users with transparency and meaningful controls over the needs it is attempting to address.
  • Openness: Blocking should maintain a level playing field and should block under the same principles regardless of source of the content. Publishers and other content providers should be given ways to participate in an open Web ecosystem, instead of being placed in a permanent penalty box that closes off the Web to their products and services.

Tell us what you think of these proposed principles on your social channels using #contentblocking and join us on Friday October 9 at 11am PT for our #BlockParty, a conversation around the problems and possible solutions to the content blocking question. We look forward to working with our users, our partners and the rest of the Web ecosystem to advance our shared goal of a healthy, open Web.

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Product Coordination Meeting This is a weekly status meeting, every Wednesday, that helps coordinate the shipping of our products (across 4 release channels) in order to ensure that...

David BurnsA new Marionette version available for Selenium Users with Java, .NET and Ruby support

If you have been wanting to use Marionette but couldn't because you don't work in Python now is your chance to do so! Well, if you are a Java User, .NET and Ruby you can use it too!! All the latest downloads of the Marionette executable are available from our development github repository releases page. We will be moving this to the Mozilla organization the closer we get to a full release.

There is also a new page on MDN that walks you through the process of setting up Marionette and using it. There are examples for all the language bindings currently supported.

Since you are awesome early adopters it would be great if we could raise bugs.

I am not expecting everything to work but below is a quick list that I know doesn't work.

  • No support for self-signed certificates
  • No support for actions
  • No support logging endpoint
  • getPageSource not available. This will be added in at a later stage, it was a slightly contentious part in the specification.
  • I am sure there are other things we don't remember

Switching of Frames needs to be done with either a WebElement or an index. Windows can only be switched by window handles. This is currently how it has been discussed in the specification.

If in doubt, raise bugs!

Thanks for being an early adopter and thanks for raising bugs as you find them!

Nick CameronRustfmt-ing Rust

Rustfmt is a tool for formatting Rust code. It has seen some rapid and impressive development over the last few months, thanks to some awesome contributions from @marcusklaas, @cassiersg, and several others. It is far from finished, but it is a powerful and useful tool. I would like Rustfmt to be a standard part of every Rustacean's toolkit. In particular, I would like Rustfmt to be used on every check-in of the Rust repo (and other large projects). For this to be possible, running Rustfmt on Rust must work without crashes, without generating poor formatting, and the whole repo must be pre-formatted so that future changes are not polluted with tonnes of formatting churn.

To work towards this, I've been running Rustfmt on some crates and modules. I would love to have some help doing this! It should be fairly easy to do with no experience with Rust or Rustfmt necessary (and you certainly don't need to know about compiler or library implementation). Hopefully you'll learn a fair bit about the Rust source code and Rustfmt in the process. This blog post is all about how to help.

For this blog post, I'll assume you don't know much about the world of Rust and go over the background etc. in a little detail. Feel free to ping me on irc or GitHub (nrc in both places) if you need any help.


The Rust repo

Can be found at It contains the source code for the Rust compiler and the standard library. When people talk about contributing to the Rust project, they often mean this repo. There are also other important repos in the rust-lang org.


Rustfmt is a tool for formatting Rust code. Rustfmt is not finished by a long shot, and there are plenty of bugs, as well as some code it doesn't even try to reformat yet. You can find the rustfmt source at

The problem

We would like to be able to run Rustfmt on the Rust repo. Ideally, we'd like to run it as part of the test suite to make sure it is properly styled. However, there are two problems with this: having not run Rustfmt on it before, there will be a lot of changes the first time it is run; and there are lots of bugs in Rustfmt which we haven't found and prevent us using it on a project the size of Rust.

The solution

Pick a module or sub-module (best to start small, I wouldn't try whole crates), run Rustfmt on it and inspect the result, if there are problems (or Rustfmt crashes while running), file an issue against Rustfmt. If it succeeds (possibly with some manual fixups), make a PR of the changes and land it!


Running rustfmt

First off you'll need to build rustfmt. For that you'll need the source code and an up to date version of the nightly compiler (scroll down to the bottom). Then to build, just run cargo build in the directory where you cloned Rustfmt. You can check it worked by running cargo test.

The most common reasons for a build failing are not using the nightly version of the compiler, or using one which is not new enough - Rustfmt lives on the bleeding edge of Rust development!

You'll also need a clone of the rust repo. Once you have that, pick a module to work on. You'll have to identify the main file for that module which will be or Then to reformat, run something like target/debug/rustfmt --write-mode=overwrite ~/rust/src/librustc_trans/save/ from the directory you installed Rustfmt in (you will need to change the path to reflect the module you want to reformat).

Rustfmt issues

If Rustfmt crashes during formatting, please get a backtrace by re-running with RUST_BACKTRACE=1. File an issue on the Rustfmt repo. If you can make a minimal test case, that is very much appreciated. The crash should tell you which file Rustfmt failed on. My technique for getting a test case is to copy that file to a temporary and cut code until I have the smallest program which still gives the same crash. Note that input to Rustfmt does not have to be valid Rust, it only needs to parse.

If formatting succeeds, then take a look at the diff to see what has been changed. You can use git diff. I find it easier to push to GitHub and look at their diff. If there are places which you think should have been re-formatted, but weren't, or which were formatted poorly, please submit an issue to the Rustfmt repo. Include the diff of the change which you think is poor, or the code which was not reformatted.

Most cases of poor formatting should block landing the changes to the Rust repo. Some cases will be acceptable, but we could do better. In those cases please file an issue and submit a PR too, but leave a reference to the issue with the PR.


Some code will need fixing up after Rustfmt is done. There are two reasons for this: in some places Rustfmt won't reformat the code yet, but it moves around surrounding code in a way which makes this a problem. In other places you might want non-standard formatting, for example if you have a 3x3 array which represents a matrix, you might want this on three lines even though rustfmt can fit it on one line.

For the first case you can manually edit the code. Check that Rustfmt preserves the changed code by running Rustfmt again and checking there are no changes.

For the second case, you can use the #[rustfmt_skip] attribute. This can be placed on functions, modules, and most other items. Again, after fixing up the source code and adding the attribute, check that Rustfmt does not make any further changes (and report as a bug if it does).

Rust PRs

And if it all works out, then submit a PR to Rust! Do this from your branch on GitHub. When submitting the PR, you can put r? @nrc in the first PR comment (or any subsequent comment) to ensure I get pinged for review. Or, if you know the files you worked on are frequently reviewed by a particular person, you can use the same method to request review from them. In that case, please cc @nrc so that I can keep track of what is getting formatted.


Some example PRs I've done and the issues filed on Rustfmt:

Mozilla WebDev CommunityUsing peep on Heroku

I recently moved a Django app to Heroku which was using peep, rather than pip, for package installation. By default Heroku will use pip to install your required packages when it sees a requirements.txt file in the root of your project, and the option to use peep instead does not exist.

Luckily one of my colleagues, pmac, was kind enough to create a share a Heroku buildpack which uses peep instead of pip for package installation. All you need to do to make use of this buildpack is issue the following command using the Heroku CLI for your app:

heroku buildpacks:set

Of course, make sure your requirements.txt is peep-compatible.

Happy peeping!

Air MozillaWebdev Extravaganza: October 2015

Webdev Extravaganza: October 2015 Once a month web developers across the Mozilla community get together (in person and virtually) to share what cool stuff we've been working on.

Patrick McManusBrotli Content-Encoding for Firefox 44

The best way to make data appear to move faster over the Web is to move less of it and lossless compression has always been a core tenet of good web design.

Sometimes that is done via over the top gzip of text resources (html, js, css), but other times it is accomplished via the compression inherent in the file format of media elements. Modern sites apply gzip to all of their text as a best practice.

Time marches on, and it turns out we can often do a better job than the venerable gzip. Until recently, new formats struggled with matching the decoding rates of gzip, but lately a new contender named brotli has shown impressive results. It has been able to improve on gzip anywhere from 20% to 40% in terms of compression ratios while keeping up on the decoding rate. Have a look at the author's recent comparative results.

The deployed WOFF2 font file format already uses brotli internally.

If all goes well in testing, Firefox 44 (ETA January 2016) will negotiate brotli as a content-encoding for https resources. The negotiation will be done in the usual way via the Accept-Encoding request header and the token "br". Servers that wish to encode a response with brotli can do so by adding "br" to the Content-Encoding response header. Firefox won't decode brotli outside of https - so make sure to use the HTTP content negotiation framework instead of doing user agent sniffing.

[edit note - around Oct 6 2015 the token was changed to br from brotli. The token brotli was only ever deployed on nightly builds of firefox 44.]

We expect Chrome will deploy something compatible in the near future.

The brotli format is defined by this document working its way through the IETF process. We will work with the authors to make sure the IANA registry for content codings is updated to reference it.

You can get tools to create brotli compressed content here and there is a windows executable I can't vouch for linked here

Yunier José Sosa VázquezXavier Martorell: “Mozilla me aporta humildad, respeto y pensamiento libre”

Xavier-MartorellEs lunes de entrevistas nuevamente y es un placer para nosotros presentarte a uno de los más jóvenes integrantes de nuestra comunidad. Estamos hablando del español Xavier Martorell o mejor dicho Yunito, como todos lo conocemos.

Pregunta:/ ¿Cómo te llamas y a qué te dedicas actualmente?

Respuesta:/ Me llamo Xavier Martorell, actualmente resido en las Islas Baleares (están ubicadas a la derecha de España), y estoy estudiando Administración y Dirección de Empresas en la Universidad de las Islas Baleares (UIB) aunque he de decir que durante el próximo año estoy pensando en irme durante un año a otro país a estudiar aunque aún no he decidido cual será.

P:/ ¿Cómo conociste de Mozilla y la comunidad?

R:/ En su día, un amigo mio que estaba mucho más concienciado que yo en temas de privacidad y protección de datos, se empeñó en que usara Mozilla Firefox por ser un navegador más seguro, libre y más respetuoso con la privacidad del usuario. Le hice caso, me informe un poco y decidí probarlo. He de decir, qué me gustó desde el primer momento por su variedad de extensiones, lo fluido que era y por todas las preocupación que tenia Mozilla acerca de la privacidad, la seguridad y su intención de un Internet libre. Así que, cuando un día, en el instituto, navegando por Internet, encontré la oportunidad de colaborar con Mozilla no lo dudé ni un segundo y decidí hacerlo.

P:/ ¿Actualmente qué labor desempeñas en la Comunidad?

R:/ Actualmente soy Responsable del Área de Control de Calidad, junto a mi amiga y mentora Gabriela Montagu, y mi labor es la de comprobar el correcto funcionamiento de las versiones de prueba en los distintos navegadores (tanto en escritorio como en Android), así como asegurarme de correcto funcionamiento de Firefox OS. También participo junto con otros miembros de Mozilla en los llamados “Testdays” que son unos días de prueba en los que se trabaja sobre alguna nueva función del navegador, así como revisar que todo lo que ya hay actualmente en Firefox funcione a la perfección. Además. estoy llevando a cabo el proyecto de Cambio de Pagina de Difusión junto con Berni, Jusai, Javfox y Miguel Useche, entre otros.

P:/ La mayoría de nosotros te conocemos por Yunito y al menos yo, pensaba que ese era tu nombre. ¿Podrías contarme más acerca de ello?

R:/ Es una historia realmente curiosa, vino de que hace ya algún tiempo me dedicaba a jugar al GTA San Andreas Multiplayer y allí existían servidores en los que podías simular otra vida tipo el juego Second Life. Para entrar tenía que inventarme un nombre, y el primer nombre que se me ocurrió fue Yunito Betancourt. Al cabo de de un tiempo me acostumbré a que la gente de Internet me llamará Yunito, así que desde entonces usé ese apodo.

P:/ Es muy interesantes esa historia, entonces te gustan los video juegos, ¿tienes algún otro pasatiempo?

R:/ Si, si quitamos mis estudios en Administración y Dirección de Empresas, así como la labor que desarrollo en Mozilla. Podría decir que mis hobbies son el estudio de la Psicología Social y el Krav Maga. Me gusta la psicología social ya que esta me permite conocer mejor el comportamiento de la sociedad, también me permite mejorar mis dotes de comunicación tanto verbal como no verbal y es una forma de saber entender y escuchar mejor a las personas. Sobre el Krav Maga, me decidí a probarlo cuando leí que era un sistema de defensa usado por el ejercito israelí y creado hace relativamente poco (hace unos 50 años, si tenemos en cuenta que el Judo tiene más de 1000…) y además muy efectivo. Desde el primer momento, me enamoré de este sistema defensa por su sencillez y efectividad y hasta día de hoy aun estoy con el.

P:/ ¿Qué es lo que más valoras o es lo más positivo de Mozilla / la Comunidad? ¿Qué te aporta a ti Mozilla / la Comunidad?

R:/ Lo que más valoro de Mozilla, así como de su comunidad, es su actitud. La definiría como una actitud positiva y amable con todo el mundo así como muy enfocada a la privacidad y la seguridad de los usuarios de los diferentes productos de Mozilla. La comunidad me aporta la oportunidad que participar en algo realmente grande en donde soy capaz de ayudar a millones de usuarios de Internet a tener un navegador que respete más sus derechos. También me aporta una serie de valores como la humildad, el respeto, el pensamiento libre, la libertad del individuo, etc. Desde que estoy en Mozilla podría decir que mi actitud hacia el mundo ha pasado de ser de un poco egocéntrica a intentar ayudar lo máximo que pueda y a preocuparme por los demás.

P:/ ¿Cómo crees que será Mozilla en el futuro?

R:/ Creo que en un futuro mucha más gente se dará cuenta de lo importante que es la privacidad para el usuario y va a querer defenderla y es por eso que mucha gente va a venir a colaborar con Mozilla y a hacer que seamos una gran comunidad en donde espero aún estar formando parte.

P:/ Unas palabras para las personas que desean unirse a la Comunidad.

R:/ Les diría que si se preocupan por su privacidad, su seguridad en Internet, sus derechos o les gusta la filosofía de Mozilla no duden en apuntarse, ya que aquí van a ser muy bien recibidos y además no se necesita tener conocimientos técnicos para ayudar a la comunidad porqué existe la posibilidad de ayudar difundiendo el mensaje de Mozilla, así como ayudando a nuevos usuarios con los diversos productos de Mozilla y muchas cosas más.

Muchas gracias Xavier Yunito por acceder a la entrevista.

Fuente: Mozilla Hispano

The Mozilla BlogMozilla Boosts Leadership Team With Connected Devices Appointment

Today, we are pleased to announce that Ari Jaaksi will be joining the Mozilla leadership team next month as our new Senior Vice President of Connected Devices.

In this role, Ari will be responsible for Firefox OS and broader exploration of opportunities to advance our mission across the ever-increasing range of connection points of the modern Internet, i.e. phones, TVs, IoT, etc.

His deep understanding of Open Source projects and mobile leadership experience at Intel, HP, and Nokia developing platforms and products make him ideally positioned to lead our Firefox OS and Connected Devices strategy.

Firefox OS is an important part of our mobile strategy, in addition to Firefox for Android and iOS and other initiatives. We believe that building an open, independent alternative to proprietary, single-vendor platforms is critical to the future of a healthy mobile ecosystem. And it is core to our mission to promote openness, innovation and opportunity in online life.

We believe Mozilla’s role in the world is more important today than it has ever been. Issues of digital rights, privacy, online safety and security are real and impact our lives daily. The pace and complexity of online life continues to accelerate from here.

Over the last year we’ve focused on building our our team to compliment the vibrant Mozillian community adding the necessary know-how to continue to bring choice, control and opportunity to everyone on the Web.

Please join me in welcoming Ari to Mozilla!

Ari’s LinkedIn Profile and Bio

Byron Joneshappy bmo push day!

the following changes have been pushed to

  • [1209332] Make the master kick-off bug “Confidential Mozilla Employee Bug” by default
  • [1209971] Suggested reviewers should exclude the current user from the list displayed
  • [1200958] group owners should always be able to view group membership reports for their groups
  • [1196620] support automatic removal of inactive users from groups
  • [1210654] “MozReview Requests” is not shown in the page after submitting a change
  • [1210762] User stories aren’t saved as part of the “remember values as bookmarkable template”
  • [1198519] Add link to bug history page to the top-right drop-down menu
  • [1210246] help link is busted
  • [1210690] Display only commits and only relevant data
  • [1205748] Can’t mark inaccessible bug dependent on a regression it caused
  • [1164063] show a warning near the attachments table for sec-high/sec-crit bugs without sec-approval? on patches
  • [1211750] Changing password with MFA turned on will not work

discuss these changes on

Filed under: bmo, mozilla

Alex ClarkI Reinstalled Again

A while back I wrote about reinstalling OS X. This is another one of those posts.

I like to reinstall OS X, a lot. So much so, you'd think I'd find some way to automate the process. There must be something soothing about it, though, because I keep doing it.

I'm writing this post now because since my last post, I've begun storing a snippets on to help automate the process. This way, I get "the best of both worlds":

  • Automation of the tedious parts &
  • Interaction with the fun parts.

Specifically, with El Capitan I've settled on these 4 snippets:





Next, I perform various additional steps manually either because I've not figured out how to automate them or the automation prospects are not attractive:

  • Security & Privacy → Allow apps downloaded from Anywhere
  • Drag /opt to Finder Favorites for easy access to Homebrew Casks, then:
    • Users & Groups → Login items → Jumpcut
  • Keyboard → Shortcuts → Mission Control → Move left a space → ⌘ ←
  • Keyboard → Shortcuts → Mission Control → Move right a space → ⌘ →
  • Dock → Terminal → Keep in Dock
  • Dock → Firefox → Keep in Dock

Still, I'd trade all these steps for full automation if I could find an approach that's not more tedious than cut & pasting the above.

Lastly, I hope this helps someone. Please add a comment below if you have a better approach.

Air MozillaParticipation Demos

Participation Demos Watch the Participation Team share what we've learned and worked on in Q3 2015.

Selena Deckelmann[berlin] TaskCluster Platform: A Year of Development

Back in September, the TaskCluster Platform team held a workweek in Berlin to discuss upcoming feature development, focus on platform stability and monitoring and plan for the coming quarter’s work related to Release Engineering and supporting Firefox Release. These posts are documenting the many discussions we had there.

Jonas kicked off our workweek with a brief look back on the previous year of development.

Prototype to Production

In the last year, TaskCluster went from an idea with a few tasks running to running all of FirefoxOS aka B2G continuous integration, which is about 40 tasks per minute in the current environment.

Architecture-wise, not a lot of major changes were made. We went from CloudAMQP to Pulse (in-house RabbitMQ). And shortly, Pulse itself will be moving it’s backend to CloudAMQP! We introduced task statuses, and then simplified them.

On the implementation side, however, a lot changed. We added many features and addressed a ton of docker worker bugs. We killed Postgres and added Azure Table Storage. We rewrote the provisioner almost entirely, and moved to ES6. We learned a lot about babel-node.

We introduced the first alternative to the Docker worker, the Generic worker. We for the first time had Release Engineering create a worker, the Buildbot Bridge.

We have several new users of TaskCluster! Brian Anderson from Rust created a system for testing all Cargo packages for breakage against release versions. We’ve had a number of external contributors create builds for FirefoxOS devices. We’ve had a few Github-based projects jump on taskcluster-github.

Features that go beyond BuildBot

One of the goals of creating TaskCluster was to not just get feature parity, but go beyond and support exciting, transformative features to make developer use of the CI system easier and fun.

Some of the features include:

Features coming in the near future to support Release

Release is a special use case that we need to support in order to take on Firefox production worload. The focus of development work in Q4 and beyond includes:

  • Secrets handling to support Release and ops workflows. In Q4, we should see go into production and UI for roles-based management.
  • Scheduling support for coalescing, SETA and cache locality. In Q4, we’re focusing on an external data solution to support coalescing and SETA.
  • Private data hosting. In Q4, we’ll be using a roles-based solution to support these.

Dave TownsendDelivering Firefox features faster

Over time Mozilla has been trying to reduce the amount of time between developing a feature and getting it into a user’s hands. Some time ago we would do around one feature release of Firefox every year, more recently we’ve moved to doing one feature release every six weeks. But it still takes at least 12 weeks for a feature to get to users. In some cases we can speed that up by landing new things directly on the beta/aurora branches but the more we do this the harder it is for release managers to track the risk of shipping a given release.

The Go Faster project is investigating ways that we can speed up getting changes to users. System add-ons are one piece of this that will let us deliver updates to core Firefox features more often than the regular six week releases. Instead of being embedded in the rest of the code certain features will be developed as standalone system add-ons.

Building features as add-ons gives us more flexibility in how we deliver the features to users. System add-ons will ship in two different ways. First every Firefox release will include a default set of system add-ons. These are the latest versions of the features at the time the Firefox build was produced. Later during runtime Firefox will contact Mozilla’s update servers to ask for the current list of system add-ons. If there are new or updated versions listed Firefox will download and install them giving users access to the newest features without needing to update the entire application.

Building a feature as an add-on gives developers a lot of benefits too. Developers will be able to work on and test new features without doing custom Firefox builds. Users can even try out new features by just installing the add-ons. Once the feature is ready to ship it ships as an add-on with no code changes necessary for integration into Firefox. This is something we’ve attempted to do before with things like Test Pilot and pdf.js, but system add-ons make this process much smoother and reduces the differences between how the feature runs as an add-on and how it runs when shipped in the application.

The basic support for system add-ons is already included in current nightly builds and Firefox 44 should be the first release that we could use to deliver features like this if we choose. If you’re interested in the details you can read the client implementation plan or follow along the tracking bug for the client side of the feature.

Air MozillaMozilla Weekly Project Meeting

Mozilla Weekly Project Meeting The Monday Project Meeting

Selena DeckelmannTaskCluster Platform: 2015Q3 Retrospective

Welcome to TaskCluster Platform’s 2015Q3 Retrospective! I’ve been managing this team this quarter and thought it would be nice to look back on what we’ve done. This report covers what we did for our quarterly goals. I’ve linked to “Publications” at the bottom of this page, and we have a TaskCluster Mozilla Wiki page that’s worth checking out.

High level accomplishments

  • Dramatically improved stability of TaskCluster Platform for Sheriffs by fixing TreeHerder ingestion logic and regexes, adding better logging and fixing bugs in our taskcluster-vcs and mozilla-taskcluster components
  • Created and Deployed CI builds on three major platforms:
    • Added Linux64 (CentOS), Mac OS X cross-compiled builds as Tier2 CI builds
    • Completed and documented a prototype Windows 2012 builds in AWS and task configuration
  • Deployed, enabling better security, better support for self-service authorization and easier contributions from outside our team
  • Added region biasing based on cost and availability of spot instances to our AWS provisioner
  • Managed the workload of two interns, and significantly mentored a third
  • Onboarded Selena as a new manager
  • Held a workweek to focus attention on bringing our environment into production support of Release Engineering

Goals, Bugs and Collaborators

We laid out our Q3 goals in this etherpad. Our chosen themes this quarter were:

  • Improve operational excellence — focus on sheriff concerns, data collection,
  • Facilitate self-serve consumption — refactoring auth and supporting roles for scopes, and
  • Exploit opportunities to differentiate from other platforms — support for interactive sessions, docker images as artifacts, github integration and more blogging/docs.

We had 139 Resolved FIXED bugs in TaskCluster product.

Link to graph of resolved bugs

We also resolved 7 bugs in FirefoxOS, TreeHerder and RelEng products/components.

We received significant contributions from other teams: Morgan (mrrrgn) designed, created and deployed taskcluster-github; Ted deployed Mac OS X cross compiled builds; Dustin reworked the Linux TC builds to use CentOS, and resolved 11 bugs related to TaskCluster and Linux builds.

An additional 9 people contributed code to core TaskCluster, intree build scripts and and task definitions: aus, rwood, rail, mshal, gerard-majax,, htsai, cmanchester, and echen.

The Big Picture: TaskCluster integration into Platform Operations

Moving from B2G to Platform was a big shift. The team had already made a goal of enabling Firefox Release builds, but it wasn’t entirely clear how to accomplish that. We spent a lot of this quarter learning things from RelEng and prioritizing. The whole team spent the majority of our time supporting others use of TaskCluster through training and support, developing task configurations and resolving infrastructure problems. At the same time, we shipped docker-worker features, provisioner biasing and a new authorization system. One tricky infra issue that John and Jonas worked on early in the quarter was a strange AWS Provisioner failure that came down to an obscure missing dependency. We had a few git-related tree closures that Greg worked closely on and ultimately committed fixes to taskcluster-vcs to help resolve. Everyone spent a lot of time responding to bugs filed by the sheriffs and requests for help on IRC.

It’s hard to overstate how important the Sheriff relationship and TreeHerder work was. A couple teams had the impression that TaskCluster itself was unstable. Fixing this was a joint effort across TreeHerder, Sheriffs and TaskCluster teams.

When we finished, useful errors were finally being reported by tasks and starring became much more specific and actionable. We may have received a partial compliment on this from philor. The extent of artifact upload retries, for example, was made much clearer and we’ve prioritized fixing this in early Q4.

Both Greg and Jonas spent many weeks meeting with Ed and Cam, designing systems, fixing issues in TaskCluster components and contributing code back to TreeHerder. These meetings also led to Jonas and Cam collaborating more on API and data design, and this work is ongoing.

We had our own “intern” who was hired on as a contractor for the summer, Edgar Chen. He did some work with the docker-worker, implementing Interactive Sessions, and did analysis on our provisioner/worker efficiency. We made him give a short, sweet presentation on the interactive sessions. Edgar is now at CMU for his sophomore year and has referred at least one friend back to Mozilla to apply for an internship next summer.

Pete completed a Windows 2012 prototype build of Firefox that’s available from Try, with documentation and a completely automated process for creating AMIs. He hasn’t created a narrated video with dueling, British-English accented robot voices for this build yet.

We also invested a great deal of time in the RelEng interns. Jonas and Greg worked with Anhad on getting him productive with TaskCluster. When Anthony arrived, we also onboarded him. Jonas worked closely to get him working on a new project, To take these two bits of work from RelEng on, I pushed TaskCluster’s roadmap for generic-worker features back a quarter and Jonas pushed his stretch goal of getting the big graph scheduler into production to Q4.

We worked a great deal with other teams this quarter on taskcluster-github, supporting new Firefox and B2G builds, RRAs for the workers and generally telling Mozilla about TaskCluster.

Finally, we spent a significant amount of time interviewing, and then creating a more formal interview process that includes a coding challenge and structured-interview type questions. This is still in flux, but the first two portions are being used and refined currently. Jonas, Greg and Pete spent many hours interviewing candidates.

Berlin Work Week

TaskCluster Platform Team in Berlin

Toward the end of the quarter, we held a workweek in Berlin to focus our next round of work on critical RelEng and Release-specific features as well as production monitoring planning. Dustin surprised us with delightful laser cut acrylic versions of the TaskCluster logo for the team! All team members reported that they benefited from being in one room to discuss key designs, get immediate code review, and demonstrate work in progress.

We came out of this with 20+ detailed documents from our conversations, greater alignment on the priorities for Platform Operations and a plan for trainings and tutorials to give at Orlando. Dustin followed this up with a series of ‘TC Topics’ Vidyo sessions targeted mostly at RelEng.

Our Q4 roadmap is focused on key RelEng features to support Release.


Our team published a few blog posts and videos this quarter:

Yunier José Sosa VázquezCómo se hace? Cambiar tu navegador predeterminado en Windows 10

La llegada de la última versión de Windows causó mucho revuelo entre los usuarios al ver que su navegador predeterminado había sido cambiado. Por su parte, Mozilla reaccionó y su CEO Chris Beard le envió una carta a su similar de Microsoft Satya Nadella pidiendo que no retrocedieran en la elección y control de los usuarios.

Las versiones actuales del panda rojo deberían cambiar esto, pero si por alguna razón no lo hace y te gustaría recuperar Firefox u otro navegador como predeterminado, te recomiendo que sigas estos pasos:

  1. Haz clic en el botón de menú menu, después selecciona Opciones.
  2. En el panel General, haz clic en Convertir en predeterminado.opciones-firefox-1
  3. La aplicación de Ajustes de Windows abrirá la pantalla de Selecciona programas predeterminados.
  4. Desplázate hacia abajo y haz clic en la entrada de Explorador web. En este caso, el icono mostrará Microsoft Edge o bien Selecciona tu navegador predeterminado.aplicaciones-predeterminadas-windows
  5. En la pantalla de Elegir una aplicación, haz clic en Firefox para establecerlo como el navegador predeterminado.elegir-firefox
  6. Firefox ahora aparece como tu navegador predeterminado. Cierra la ventana para guardar tus cambios.

Y listo, ya tendrás Firefox de vuelta como tu navegador predeterminado y preferido.

Fuente: Mozilla Support

The Servo BlogThis Week In Servo 36

In the last week, we landed 69 PRs in the Servo repository!

Glenn wrote a short report on how webrender is coming along. Webrender is a new renderer for Servo which is specialized for web content. The initial results are quite promising!

Notable additions

New Contributors


Snazzy new form widgets:


At last week’s meeting, we discussed webrender, and pulling app units out into a separate crate.

Daniel StenbergTalked HTTP/2 at ApacheCon

I was invited as one of the speakers at the ApacheCon core conference in Budapest, Hungary on October 1-2, 2015.


I was once again spreading the news about HTTP/2, why it was made and how it works and of course: updated numbers on adoption right now.

The talk was unfortunately not filmed, but I’ve put my slides for this version of my talk online. Readers of this blog and those who’ve seen my presentations before will recognize large parts of it.

Following my talk was talks about mod_http2, the Apache module for HTTP/2 that will be coming in the upcoming 2.4.17 release of Apache Httpd, explained by its author Stefan Eissing. The name of the module was actually a bit of a surprise to me since it has been known as just mod_h2 for its entire life time up until now.

William A Rowe took us through the state of TLS for the main Apache servers and yeah, the state seem to be pretty good and they’re coming along really well. TLS and then HTTPS is important as that’s really a prerequisite for HTTP/2

I also got to listen to Mark Thomas explain the agonies of making Tomcat support HTTP/2, and then perhaps especially how ALPN and a good set of ciphers are hard to get in Java.

Jean-Frederic Clere then explained how to activate HTTP/2 on all the Apache servers (tomcat, httpd and traffic server) and a little about their HTTP/2 state, following with an explanation how they worked on tomcat to make that use OpenSSL for the TLS layer (including ALPN) to avoid the deadlock of decent TLS support in Java.

All in all, a great track and splendid talks with deep technical content. Exactly the way I like it. Thanks everyone. Apachecon certainly delivered for me! Twas fun.

Julien VehentSHA1/SHA256 certificate switching with HAProxy

SHA-1 certificates are on their way out, and you should upgrade to a SHA-256 certificate as soon as possible... unless you have very old clients and must maintain SHA-1 compatibility for a while.

If you are in this situation, you need to either force your clients to upgrade (difficult) or implement some form of certificate selection logic: we call that "cert switching".

The most deterministic selection method is to serve SHA-256 certificates to clients that present a TLS1.2 CLIENT HELLO that explicitly announces their support for SHA256-RSA (0x0401) in the signature_algorithms extension.


Modern web browsers will send this extension. However, I am not aware of any open source load balancer that is currently able to inspect the content of the signature_algorithms extension. It may come in the future, but for now the easiest way to achieve cert switching is to use HAProxy SNI ACLs: if a client presents the SNI extension, direct it to a backend that presents a SHA-256 certificate. If it doesn't present the extension, assume that it's an old client that speaks SSLv3 or some broken version of TLS, and present it a SHA-1 cert.

This can be achieved in HAProxy by chaining frontend and backends:



frontend https-in
        mode tcp
        tcp-request inspect-delay 5s
        tcp-request content accept if { req_ssl_hello_type 1 }
        use_backend jve_https if { req.ssl_sni -i }

        # fallback to backward compatible sha1
        default_backend jve_https_sha1

backend jve_https
        mode tcp
        server jve_https
frontend jve_https
        bind ssl no-sslv3 no-tlsv10 crt /etc/haproxy/certs/jve_sha256.pem tfo
        mode http
        option forwardfor
        use_backend jve

backend jve_https_sha1
        mode tcp
        server jve_https
frontend jve_https_sha1
        mode http
        option forwardfor
        use_backend jve

backend jve
        rspadd Strict-Transport-Security:\ max-age=15768000
        server jve maxconn 128

The configuration above receives inbound traffic in the frontend called "https-in". That frontend is in TCP mode and inspects the CLIENT HELLO coming from the client for the value of the SNI extension. If that value exists and matches our target site, it sends the connection to the backend named "jve_https", which redirects to a frontend also named "jve_https" where the SHA256 certificate is configured and served to the client.

If the client fails to present a CLIENT HELLO with SNI, or presents a SNI that doesn't match our target site, it is redirected to the "https_jve_sha1" backend, then to its corresponding frontend where a SHA1 certificate is served. That frontend also supports an older ciphersuite to accommodate older clients.

Both frontends eventually redirect to a single backend named "jve" which sends traffic to the destination web servers.

This is a very simple configuration, and eventually it could be improved using better ACLs (HAproxy regularly adds news ones), but for a basic cert switching configuration, it gets the job done!

Julian SewardDr Memory: a memory-checking tool for Windows

Valgrind’s Memcheck tool works on Linux and MacOS, but not on Windows. Interestingly, there is something like it for Windows: “Dr Memory”.  Similar in style to Memcheck, Dr Memory is an open source memory checking tool built on top of a JIT-based instrumentation framework called DynamoRIO. It provides essentially identical functionality: detection of invalid memory accesses, uninitialised value uses and memory leaks. Dr Memory claims to be considerably faster than Memcheck, so I was curious to see how it performed.

I recently tried Dr Memory 1.9.0-RC1 on Windows 7, running 32-bit Firefox builds, to see to what extent it can provide coverage for the Windows-specific parts of Gecko.

Installing and getting started isn’t difficult. There are command line flags to direct the output, control the level of instrumentation, specify files listing errors to hide, and so on. As you’d expect.

Despite considerable efforts with Dr Memory, I came away feeling it was a promising tool, but just a bit too hard to use. I encountered two kinds of problems.

Firstly, about half of my Firefox startups ended up spinning. Some of the time, Firefox would start (slowly, of course) and be usable after a couple of minutes. Other runs would spin for an hour or more and still not produce a usable browser. I never figured out why. This seems to be related to the instrumentation, because if I run Firefox uninstrumented on the DynamoRIO core, like Valgrind’s –tool=none, it works reliably.

A second problem was the considerable number of uninitialised memory read errors. I tried out both non-optimised (“/Zi /Od”) and optimised (“/Zi /O2 /Oy- /Ob0”) builds of Firefox.

For the non-optimised builds, Dr Memory reports no invalid accesses and a few uninitialised memory reads, which is what I’d expect. But it’s unusably slow, because the unoptimised build lacks reasonable register allocation, which easily doubles the number of memory accesses that have to be checked.

So my next step was to try an optimised build. This runs a great deal faster. There’s a down side, though: the number of uninitialised memory accesses goes way up. Most of these must be false positives, because they weren’t reported in the unoptimised runs.

I investigated further. It is likely that one source of false positives is Dr Memory’s incomplete description of the Windows system call interface. Valgrind’s description of the Linux syscall interface is itself complex, and it is said that the Windows interface makes the Linux interface look simple. Given that, I’m impressed that Dr Memory works as well as it does.

The other source of false positives appears to be bitfields. Dr Memory tracks the definedness state of each byte of memory using one bit for each byte. Consequently it has no way to accurately model partially initialised bytes, and so must unavoidably either report false positives, or miss real errors, depending on which of the two available shadow states partially initialised bytes are mapped to.

One way to detect probable false-positive bitfield errors in cross platform Gecko code is to check whether Memcheck reports errors at the same places. In many cases it doesn’t. I created a suppressions file, which tells Dr Memory to hide errors I identified as clearly false. A second line of defense is to add extra initialisation code for bitfields purely in order to keep Dr Memory happy. Neither of these are really what one wants to do, though.

The false positive problem seriously compromises Dr Memory’s usefulness on optimised Gecko code, compared to Memcheck. The effect is to create a lot more undefined value errors needing investigation. The situation is exacerbated because Dr Memory doesn’t have an equivalent to Memcheck’s origin-tracking feature, which makes it more difficult to analyse the errors and to determine where, if any, dummy initialisations should be placed.

Dr Memory does have a “light” mode, which restricts it to invalid-address and leak checking only. This increases usability at the expense of losing undefined value checking. If you’re looking for possible heap corruption on Windows, this would be worth a try.

QMOFirefox 42.0 Beta 3 Testday Results

Hello Mozillians!

As you may already know, last Friday – October 2nd – we held a new Testday event, for Firefox 42 Beta 3.

I must admit that this testday is by far one of the most successful event. Besides the fact that we had a large number of participants we also have an impressive number of verified bugs. Congratulations to all participants!


We’d like to take this opportunity to thank Bolaram Paul, Mohammed Adam , Ionce Stelian, Ruwan Ranganath, Jayesh KR, Arshad Abid, Moin Shaikh, Syed Muhammad Mahmudul Haque (Yamin), Nischaytv, Jyotsna Gupta, PreethiDhinesh, Kevin Le, Gunjan Tank and the people from our Bangladesh Community: Hossain Al Ikram, Khalid Syfullah Zaman, Ashickur Rahman, Md. Asiful Kabir, Rezaul Huque Nayeem, Kazi Nuzhat Tasnem, Nazir Ahmed Sabbir, Saheda Reza Antora, Md.Ehsanul Hassan, Mohammad Maruf Islam, Sayed Mohammad Amir, Meraj  Kazi, Forhad Hossain, T.M. Sazzad Hossain and Towkir Ahmed for getting involved in this event and making Firefox as best as it could be.

Also a big thank you goes to all our active moderators.

Keep an eye on QMO for upcoming events!

Andy McKayAm I better off?

It seems to be a common theme in elections for the incumbent party to ask the question, "Are you better off?". The Conservatives have been in power now since the 2006 election.

Financially? I'm better off, due to having a decent paying job in a company not based in Canada. The economy is moving along despite a Conservative running multiple deficits in a row. Really, I don't place too much faith in the Government to do a huge amount to the economy, no matter what the Conservative attack adverts say.

Privacy? Much worse off, the Government have introduced multiple bills to reduce our privacy, none worse than bill C-51 which greatly increases the Government spying powers and reduces the amount of oversight.

Rights? Much worse off, the Government introduced bill C-24 which means that the citizenship of me (and most of my friends and colleagues) can now be revoked. We are all second class citizens and not "old stock canadians". The reduction of our charter of rights and freedoms is breathtaking.

Environment? We are the only country in the world to withdraw from Kyoto and become isolated Canada on the world stage. There's the oil sands turning Alberta into Mordor, there's been major oil spills, the tragic Lac-Mégantic incident, the proposed pipelines and so on. And of course environmentalists are terrorists.

Science? The census was gutted and decisions are not made on data, but ideology.

Right now? I am worse off. I have much less security and privacy than before. So no, I won't be voting Conservative and I'm not sure why anyone would.

This Week In RustThis Week in Rust 99

Hello and welcome to another issue of This Week in Rust! Rust is a systems language pursuing the trifecta: safety, concurrency, and speed. This is a weekly summary of its progress and community. Want something mentioned? Tweet us at @ThisWeekInRust or send us an email! Want to get involved? We love contributions.

This Week in Rust is openly developed on GitHub. If you find any errors in this week's issue, please submit a PR.

This week's edition was edited by: nasa42, brson, and llogiq.

Updates from Rust Community

News & Blog Posts

Notable New Crates & Projects

  • Redox. A Rust Operating System.
  • Webrender. An experimental renderer for Servo that aims to draw web content like a modern game engine.
  • Coroutine I/O. Coroutine scheduling with work-stealing algorithm.
  • Rustation. PlayStation emulator in Rust.

Updates from Rust Core

102 pull requests were merged in the last week.

See the subteam report for 2015-10-02 for details.

Notable changes

New Contributors

  • Andreas Sommer
  • Dato Simó
  • James Bell
  • Jethro Beekman
  • Seeker14491
  • Ted Mielczarek
  • Will Speak
  • Willy Aguirre

Approved RFCs

Changes to Rust follow the Rust RFC (request for comments) process. These are the RFCs that were approved for implementation this week:

No RFCs were approved this week!

Final Comment Period

Every week the team announces the 'final comment period' for RFCs and key PRs which are reaching a decision. Express your opinions now. This week's FCPs are:

New RFCs

Upcoming Events

If you are running a Rust event please add it to the calendar to get it mentioned here. Email Erick Tryzelaar or Brian Anderson for access.

fn work(on: RustProject) -> Money

No jobs listed for this week. Tweet us at @ThisWeekInRust to get your job offers listed here!

Crate of the Week

This week, Crate of the Week is Itertools. Thanks go to llogiq for the suggestion. In his own words:

So today I'll write about Itertools. Because iterators in Rust are awesome, and this crates makes them even awesome-r. If you want to do something with iterators that seems to be slightly impossible using the std APIs, chances are Itertools already implements a way that is both fast and elegant. Knowing your itertools APIs will level up your Rust-fu.

For a (very small and simple) example, haven't you wished to zip two iterators, but don't stop iteration after the shorter iterator has run out? With Itertools you can just say x.zip_longest(y) and get an iterator of EitherOrBoth<X, Y>.

Quote of the Week

In programming (as opposed to politics), safety=freedom.llogiq on /r/rust.

Thanks to birkenfeld for the tip. Submit your quotes for next week!

Mike ConleyThe Joy of Coding – Ep’s 23 – 29

Wow! I’ve been a way from this blog for too long. I also haven’t posted any new episodes for The Joy of Coding. I also haven’t been keeping up with my Things I’ve Learned posts.

Time to get back in the saddle. First thing’s first, here are 6 episodes of The Joy of Coding that have aired. Unfortunately, I haven’t put together summaries for any of them, but I’ve put their agendas near the videos so that might give some clues.

Here we go!

Episode 23


Episode 24


Episode 25


Episode 26


Episode 27


Episode 28


Episode 29


Yunier José Sosa VázquezVI Taller Internacional de Tecnologías de Software Libre y Código Abierto

Como parte de la XVI Convención y Feria Internacional Informática Habana 2016 a realizarse en nuestra capital a partir del 14 y hasta el 18 de marzo de 2016, se desarrollará el VI Taller Internacional de Tecnologías de Software Libre y Código Abierto, un evento donde las personas podrán debatir en torno a diferentes temáticas como por ejemplo: la adopción de tecnologías de software libre y código abierto, el desarrollo y personalización de sistemas operativos, y aspectos económicos, legales y sociales.

informatica2016-logoComo parte del taller de software libre y código abierto en las temáticas se tratará lo siguiente:

  1. Adopción de tecnologías de software libre y código abiertoExperiencias en la conducción y ejecución de procesos de migración a aplicaciones de software libre y código abierto. Implantación de tecnologías libres en el sector público y privado. Modelos de madurez para la selección de tecnologías libres. Rol del software libre en el desarrollo sostenible.
  2. Construcción / personalización de sistemas operativos basados en fuentes abiertasDesarrollo de sistemas operativos libres a la medida para computadoras de escritorio, servidores y teléfonos móviles. Software libre embebido. Construcción de distribuciones GNU/Linux.
  3. Aspectos económicos, legales y socialesEstudios de viabilidad económica para la adopción de software libre. Modelos de negocios aplicables. Impacto social del software libre. Propiedad intelectual, derecho de autor y licenciamiento de tecnologías libres. Marco regulativo para el empleo de software libre.
  4. Tecnologías de software libreSoftware libre para la nube, seguridad en tecnologías libres. Estándares abiertos en el desarrollo de soluciones. OpenData. OpenCloud. Tecnologías de gestión de datos en código abierto. Software libre como servicio, aplicaciones empresariales de fuentes abiertas. Tecnologías móviles de código abierto.

Desde la página web del evento también se puede observar varios datos útiles para las personas que deseen participar entre los que destacan:

Fechas Importantes

  • Presentación de resúmenes y ponencias: 20 de octubre de 2015
  • Notificación de aceptación: 20 de noviembre de 2015
  • Envío del trabajo final para su publicación: 7 de diciembre de 2015

Pautas de Redacción

Los trabajos se presentarán a partir de las temáticas principales de los distintos eventos a realizarse en el marco de la Convención, teniendo en cuenta las siguientes especificaciones:

  • Deben entregarse en ficheros compatibles con formato de documento abierto
  • Límite de 10 hojas
  • El tamaño de la hoja será tipo carta (8,5” x 11” ó 21,59 cm. x 27,94 cm.), con márgenes de 2 cm. por cada lado y escrito a dos columnas
  • Deberá utilizarse tipografía Arial a 11 puntos para los encabezados y a 10 puntos para los textos, con un interlineado sencillo
  • Se redactará en los idiomas del evento (español o inglés)

Estructura de los trabajos:

  • Título
  • Título (en inglés)
  • Autor y coautores
  • Afiliación y datos de contactos
  • Resumen y Palabras Claves (en español y en inglés)
  • Introducción
  • Contenido
  • Conclusiones
  • Agradecimientos (opcional)
  • Referencias bibliográficas

Para facilitar la elaboración de su trabajo conforme a las especificaciones de la Convención, tiene que descargar la plantilla y sustituya sus textos. .doc

Usted deberá enviar su trabajo a través de la Plataforma para la Gestión de Ponencias, recuerde que debe adjuntar además una síntesis curricular del autor principal. Las presentaciones de los trabajos a exponer en el evento presencial deben ser entregados por los ponentes en la Oficina de Recepción de Medios Audiovisuales, en el Palacio de Convenciones, un día antes de la exposición en sala. Las conferencias, presentaciones y otros materiales de la Convención se publicarán en un disco compacto con su registro ISBN.

Luis VillaSoftware that liberates people: feels about FSF@30 and OSFeels@1

tl;dr: I want to liberate people; software is a (critical) tool to that end. There is a conference this weekend that understands that, but I worry it isn’t FSF’s.

Feelings are facts, by wrote, CC BY 2.0

This morning, social network chatter reminded me of FSF‘s 30th birthday celebration. These travel messages were from friends who I have a great deal of love and respect for, and represent a movement to which I essentially owe my adult life.

Despite that, I had lots of mixed feels about the event. I had a hard time capturing why, though.

While I was still processing these feelings, late tonight, Twitter reminded me of a new conference also going on this weekend, appropriately called Open Source and Feelings. (I badly wanted to submit a talk for it, but a prior commitment kept me from both it and FSF@30.)

I saw the OSFeels agenda for the first time tonight. It includes:

  • Design and empathy (learning to build open software that empowers all users, not just the technically sophisticated)
  • Inclusive development (multiple talks about this, including non-English, family, and people of color) (so that the whole planet can access, and participate in developing, open software)
  • Documentation (so that users understand open software)
  • Communications skills (so that people feel welcome and engaged to help develop open software)

This is an agenda focused on liberating human beings by developing software that serves their needs, and engaging them in the creation of that software. That is incredibly exciting. I’ve long thought (following Sen and Nussbaum’s capability approach) that it is not sufficient to free people; they must be empowered to actually enjoy the benefits of that freedom. This is a conference that seems to get that, and I can’t wait to go (and hopefully speak!) next year.

The Free Software Foundation event’s agenda:

  • licenses
  • crypto
  • boot firmware
  • federation

These are important topics. But there is clearly a difference in focus here — technology first, not people. No mention of community, or of design.

This difference in focus is where this morning’s conflicted feels came from. On the one hand, I support FSF, because they’ve done an incredible amount to make the world a better place. (OSFeels can take open development for granted precisely because FSF fought so many battles about source code.) But precisely because I support FSF, I’d challenge it, in the next 15 years, to become more clearly and forcefully dedicated to liberating people. In this world, FSF would talk about design, accessibility, and inclusion as much as licensing, and talk about community-building protocols as much as communication protocols. This is not impossible: LibrePlanet had at least some people-focused talks (e.g.), and inclusion and accessibility are a genuine concern of staff, even if they didn’t rise to today’s agenda. But it would still be a big change, because at the deepest level, it would require FSF to see source code as just one of many requirements for freedom, rather than “the point of free software“.

At the same time, OSFeels is clearly filled with people who see the world through a broad, thoughtful ethical lens. It is a sad sign, both for FSF and how it is perceived, that such a group uses the deliberately apolitical language of openness rather than the language of a (hopefully) aligned ethical movement — free software. I’ll look forward to the day (maybe FSF’s 45th (or 31st!) birthday) that both groups can speak and work together about their real shared concern: software that liberates people. I’d certainly have no conflicted feelings about signing up for a conference on that :)

David HumphreyHow to become a Fool Stack Programmer

At least once in your career as a programmer, and hopefully more than once and with deliberate regularity, it is important to leave the comfort of your usual place along the stack and travel up or down it. While you usually fix bugs and add features using a particular application, tool, or API and work on top of some platform, SDK, or operating system, this time you choose to climb down a wrung and work below. In doing so you are working on instead of with something.

There are a number of important outcomes of changing levels. First, what you previously took for granted, and simply used as such, suddenly comes into view as a thing unto itself. This layer that you've been standing on, the one that felt so turns out to have also have been built, just like the things you build from above! It sounds obvious, but in my experience, the effect it has on your approach from this point forward is drastically changed. Second, and very much related to the first, your likelihood to lash out when you encounter bugs or performance and implementation issues gets abated. You gain empathy and understanding.

If all you ever do is use an implementation, tool, or API, and never build or maintain one, it's easy to take them for granted, and speak about them in detached ways: Why would anyone do it this way? Why is this so slow? Why won't they fix this bug after 12 years! And then, Why are they so stupid as to have done this thing?

Now, the same works in the other direction, too. Even though there are more people operating at the higher level and therefore need to descend to do what I'm talking about, those underneath must also venture above ground. If all you've ever done is implement things, and never gone and used such implementations to build real things, you're just as guilty, and equally, if not more likely to snipe and complain about people above you, who clearly don't understand how things really work. It's tantalizingly easy to dismiss people who haven't worked at your level: it's absolutely true that most of them don't understand your work or point of view. The way around this problem is not to wait and hope that they will come to understand you, but to go yourself, and understand them.

Twitter, HN, reddit, etc. are full of people at both levels making generalizations, lobbing frustration and anger at one another, and assuming that their level is the only one that actually matters (or exists). Fixing this problem globally will never happen; but you can do something at the personal level.

None of us enjoys looking foolish or revealing our own ignorance. And one of the best ways to avoid both is to only work on what we know. What I'm suggesting is that you purposefully move up or down the stack and work on code, and with tools, people, and processes that you don't know. I'm suggesting that you become a Fool, at least in so far as you allow yourself to be humbled by this other world, with its new terminology, constraints, and problems. By doing this you will find that your ability to so easily dismiss the problems of the other level will be greatly reduced. Their problems will become your problems, and their concerns your concerns. You will know that you've correctly done what I'm suggesting when you start noticing yourself referring to "our bug" and "how we do this" instead of "their" and "they."

Becoming a Fool Stack Programmer is not about becoming an expert at every level of the stack. Rather, its goal is to erase the boundary between the levels such that you can reach up or down in order to offer help, even if that help is only to offer a kind word of encouragement when the problem is particularly hard: these are our problems, after all.

I'm grateful to this guy who first taught me this lesson, and encouraged me to always keep moving up the stack.

Jan de MooijBye Wordpress, hello Jekyll!

This week I migrated this blog from Wordpress to Jekyll, a popular static site generator. This post explains why and how I did this, maybe it will be useful to someone.


Wordpress powers thousands of websites, is regularly updated, has a ton of features. Why did I abandon it?

I still think Wordpress is great for a lot of websites and blogs, but I felt it was overkill for my simple website. It had so many features I never used and this came at a price: it was hard to understand how everything worked, it was hard to make changes and it required regular security updates.

This is what I like most about Jekyll compared to Wordpress:

  • Maintainance, security: I don't blog often, yet I still had to update Wordpress every few weeks or months. Even though the process is pretty straight-forward, it got cumbersome after a while.
  • Setup: Setting up a local Wordpress instance with the same content and configuration was annoying. I never bothered so the little development I did was directly on the webserver. This didn't feel very good or safe. Now I just have to install Jekyll, clone my repository and generate plain HTML files. No database to setup. No webserver to install (Jekyll comes with a little webserver, see below).
  • Transparency: With Wordpress, the blog posts were stored somewhere in a MySQL database. With Jekyll, I have Markdown files in a Git repository. This makes it trivial to backup, view diffs, etc.
  • Customizability: After I started using Jekyll, customizing this blog (see below) was very straight-forward. It took me less than a few hours. With Wordpress I'm sure it'd have taken longer and I'd have introduced a few security bugs in the process.
  • Performance: The website is just some static HTML files, so it's fast. Also, when writing a blog post, I like to preview it after writing a paragraph or so. With Wordpress it was always a bit tedious to wait for the website to save the blog post and reload the page. With Jekyll, I save the markdown file in my text editor and, in the background, jekyll serve immediately updates the site, so I can just refresh the page in the browser. Everything runs locally.
  • Hosting: In the future I may move this blog to GitHub Pages or another free/cheaper host.

Why Jekyll?

I went with Jekyll because it's widely used, so there's a lot of documentation and it'll likely still be around in a year or two. Octopress is also popular but under the hood it's just Jekyll with some plugins and changes, and it seems to be updated less frequently.


I decided to use the default template and customize it where needed. I made the following changes:

  • Links to previous/next post at the end of each post, see post.html
  • Pagination on the homepage, based on the docs. I also changed the home page to include the contents instead of just the post title.
  • Archive page, a list of posts grouped by year, see archive.html
  • Category pages. I wrote a small plugin to generate a page + feed for each category. This is based on the example in the plugin documentation. See _plugins/category-generator.rb and _layouts/category.html
  • List of categories in the header of each post (with a link to the category page), see post.html
  • Disqus comments and number of comments in the header of each post, based on the docs, see post.html. I was able to export the Wordpress comments to Disqus.
  • In _config.yml I changed the post URL format ("permalink" option) to not include the category names. This way links to my posts still work.
  • Some minor tweaks here and there.

I still want to change the code highlighting style, but that can wait for now.


After using Jekyll for a few hours, I'm a big fan. It's simple, it's fun, it's powerful. If you're tired of Wordpress and Blogger, or just want to experiment with something else, I highly recommend giving it a try.

Mozilla Addons BlogAdd-on Compatibility for Firefox 42

Firefox 42 will be released on November 3rd. Here’s the list of changes that went into this version that can affect add-on compatibility. There is more information available in Firefox 42 for Developers, so you should also give it a look.



  • Split nsIContentPolicy::TYPE_SUBDOCUMENT into TYPE_FRAME and TYPE_IFRAME. This should only affect your add-on if it implements nsIContentPolicy.
  • Use origin for nsIPermissionManager. Permissions in the Permission Manager used to be handled per-host, and now they will be handled per-origin. This means that and have different permission entries. This changes some methods in the Permission Manager so they accept URIs instead of strings.
  • Update: nsINetUtil.parseContentType has been renamed to parseResponseContentType as part of a security fix. Its behavior should remain the same.


Please let me know in the comments if there’s anything missing or incorrect on these lists. If your add-on breaks on Firefox 42, I’d like to know.

The automatic compatibility validation and upgrade for add-ons on AMO will happen in the coming weeks, so keep an eye on your email if you have an add-on listed on our site with its compatibility set to Firefox 41.

Joel MaherHacking on a defined length contribution program

Contribution takes many forms where each person has different reasons to contribute or help people contribute.  One problem we saw a need to fix was when a new contributor came to Mozilla and picked up a “good first bug”, then upon completion was left not knowing what to do next and picking up other random bugs.  The essential problem is that we had no clear path defined for someone to start making more substantial improvements to our projects.   This can easily lead toward no clear mentorship as well as a lot of wasted time setting up and learning new things.  In response to this, we decided to launch the Summer of Contribution program.

Back in May we announced two projects to pilot this new program: perfherder and developer experience.  In the announcement we asked that interested hackers commit to dedicating 5-10 hours/week for 8 weeks to one of these projects. In return, we would act as a dedicated mentor and do our best to ensure success.

I want to outline how the program was structured, what worked well, and what we want to do differently next time.

Program Structure

The program worked well enough, with some improvising, here is what we started with:

  • we created a set of bugs that would be good to get new contributors started and working for a few weeks
  • anybody could express interest via email/irc, we envisioned taking 2-3 participants based on what we thought we could handle as mentors.

That was it, we improvised a little by doing:

  • accepting more than 2-3 people to start (4-6)- we had a problem saying no
  • folks got ramped up and just kept working (there was no official start date)
  • blogging about who was involved and what they would be doing (intro to the perfherder team, intro to the dx team)
  • setting up communication channels with contributors like etherpad, email, wunderlist, bugzilla, irc
  • setting up regular meetings with contributors
  • picking an end date
  • summarizing the program (wlach‘s perfherder post, jmaher’s dx post

What worked well

A lot worked very well, specifically advertising by blog post and newsgroup post and then setting the expectation of a longer contribution cycle rather than a couple weeks.  Both :wlach and myself have had a good history of onboarding contributors, and feel that being patient, responding quickly, communicating effectively and regularly, and treating contributors as team members goes a long way.  Onboarding is easier if you spend the time to create docs for setup (we have the ateam bootcamp).  Without mentors being ready to onboard, there is no chance for making a program like this work.

Setting aside a pile of bugs to work on was successful.  The first contribution is hard as there is so much time required for setup, so many tools and terms to get familiar with, and a lot of process to learn.  After the first bug is completed, what comes next?  Assuming it was enjoyable, one of two paths usually take place:

  • Ask what is next to the person that reviewed your code or was nice to you on IRC
  • Find another bug and ask to work on it

Both of these are OK models, but there is a trap where you could end up with a bug that is hard to fix, not well defined, outdated/irrelevant, or requires a lot of new learning/setup.  This trap is something to avoid where we can build on the experience of the first bug and work on the same feature but on a bug that is a bit more challenging.

A few more thoughts on the predefined set of bugs to get started:

  • These should not be easily discoverable as “good first bugs“, because we want people who are committed to this program to work on them, rather than people just looking for an easy way to get involved.
  • They should all have a tracking bug, tag, or other method for easily seeing the entire pool of bugs
  • All bugs should be important to have fixed, but they are not urgent- think about “we would like to fix this later this quarter or next quarter”.  If we do not have some form of urgency around getting the bugs fixed, our eagerness to help out in mentoring and reviewing will be low.  A lot of  times while working on a feature there are followup bugs, those are good candidates!
  • There should be an equal amount (5-10) of starter bugs, next bugs, and other bugs
  • Keep in mind this is a starter list, imagine 2-3 contributors hacking on this for a month, they will be able to complete them all.
  • This list can grow as the project continues

Another thing that worked is we tried to work in public channels (irc, bugzilla) as much as possible, instead of always private messaging or communicating by email. Also communicating to other team members and users of the tools that there are new team members for the next few months. This really helped the contributors see the value of the work they are doing while introducing them to a larger software team.

Blog posts were successful at communicating and helping keep things public while giving more exposure to the newer members on the team.  One thing I like to do is ensure a contributor has a Mozillians profile as well as links to other discoverable things (bugzilla id, irc nick, github id, twitter, etc.) and some information about why they are participating.  In addition to this, we also highlighted achievements in the fortnightly Engineering Productivity meeting and any other newsgroup postings we were doing.

Lastly I would like to point out a dedicated mentor was successful.  As a contributor it is not always comfortable to ask questions, or deal with reviews from a lot of new people.  Having someone to chat with every day you are hacking on the project is nice.  Being a mentor doesn’t mean reviewing every line of code, but it does mean checking in on contributors regularly, ensuring bugs are not stuck waiting for needinfo/reviews, and helping set expectations of how work is to be done.  In an ideal world after working on a project like this a contributor would continue on and try to work with a new mentor to grow their skills in working with others as well as different code bases.

What we can do differently next time?

A few small things are worth improving on for our next cycle, here is a few things we will plan on doing differently:

  • Advertising 4-5 weeks prior and having a defined start/end date (e.g. November 20th – January 15th)
  • Really limiting this to a specific number of contributors, ideally 2-3 per mentor.
  • Setting acceptance criteria up front.  This could be solving 2 easy bugs prior to the start date.
  • Posting an announcement welcoming the new team members, posting another announcement at the halfway mark, and posting a completion announcement highlighting the great work.
  • Setting up a weekly meeting schedule that includes status per person, great achievements, problems, and some kind of learning (guest speaker, Q&A, etc.).  This meeting should be unique per project.
  • Have a simple process for helping folks transition out of they have less time than they thought- this will happen, we need to account for it so the remaining contributors get the most out of the program.

In summary we found this to be a great experience and are looking to do another program in the near future.  We named this Summer of Contribution for our first time around, but that is limiting to when it can take place and doesn’t respect the fact that the southern hemisphere is experiencing Winter during that time.  With that :maja_zf suggested calling it Quarter of Contribution which we plan to announce our next iteration in the coming weeks!

Will Kahn-GreeneDennis v0.7 released! New lint rules and more tests!

What is it?

Dennis is a Python command line utility (and library) for working with localization. It includes:

  • a linter for finding problems in strings in .po files like invalid Python variable syntax which leads to exceptions
  • a template linter for finding problems in strings in .pot files that make translator's lives difficult
  • a statuser for seeing the high-level translation/error status of your .po files
  • a translator for strings in your .po files to make development easier

v0.7 released!

It's been 10 months since the last release. In that time, I:

  • Added a lot more tests and fixed bugs discovered with those tests.
  • Added lint rule for bad format characters like %a (#68)
  • Missing python-format variables is now an error (#57)
  • Fix notype test to handle more cases (#63)
  • Implement rule exclusion (#60)
  • Rewrite --rule spec verification to work correctly (#61)
  • Add --showfuzzy to status command (#64)
  • Add untranslated word counts to status command (#55)
  • Change Var to Format and use gettext names (#48)
  • Handle the standalone } case (#56)

I thought I was close to 1.0, but now I'm less sure. I want to unify the .po and .pot linters and generalize them so that we can handle other l10n file formats. I also want to implement a proper plugin system so that it's easier to add new rules and it'd allow other people to create separate Python packages that implement rules, tokenizers and translaters. Plus I want to continue fleshing out the tests.

At the (glacial) pace I'm going at, that'll take a year or so.

If you're interested in dennis development, helping out or have things you wish it did, please let me know. Otherwise I'll just keep on keepin on at the current pace.

Where to go for more

For more specifics on this release, see here:

Documentation and quickstart here:

Source code and issue tracker here:

Source code and issue tracker for Denise (Dennis-as-a-service):

47 out of 80 Silicon Valley companies say their last round of funding depended solely on having dennis in their development pipeline and translating their business plan into Dubstep.

Daniel PocockWant to be selected for Google Summer of Code 2016?

I've mentored a number of students in 2013, 2014 and 2015 for Debian and Ganglia and most of the companies I've worked with have run internships and graduate programs from time to time. GSoC 2015 has just finished and with all the excitement, many students are already asking what they can do to prepare and be selected for Outreachy or GSoC in 2016.

My own observation is that the more time the organization has to get to know the student, the more confident they can be selecting that student. Furthermore, the more time that the student has spent getting to know the free software community, the more easily they can complete GSoC.

Here I present a list of things that students can do to maximize their chance of selection and career opportunities at the same time. These tips are useful for people applying for GSoC itself and related programs such as GNOME's Outreachy or graduate placements in companies.


There is no guarantee that Google will run the program again in 2016 or any future year until the Google announcement.

There is no guarantee that any organization or mentor (including myself) will be involved until the official list of organizations is published by Google.

Do not follow the advice of web sites that invite you to send pizza or anything else of value to prospective mentors.

Following the steps in this page doesn't guarantee selection. That said, people who do follow these steps are much more likely to be considered and interviewed than somebody who hasn't done any of the things in this list.

Understand what free software really is

You may hear terms like free software and open source software used interchangeably.

They don't mean exactly the same thing and many people use the term free software for the wrong things. Not all projects declaring themselves to be "free" or "open source" meet the definition of free software. Those that don't, usually as a result of deficiencies in their licenses, are fundamentally incompatible with the majority of software that does use genuinely free licenses.

Google Summer of Code is about both writing and publishing your code and it is also about community. It is fundamental that you know the basics of licensing and how to choose a free license that empowers the community to collaborate on your code well after GSoC has finished.

Please review the definition of free software early on and come back and review it from time to time. The The GNU Project / Free Software Foundation have excellent resources to help you understand what a free software license is and how it works to maximize community collaboration.

Don't look for shortcuts

There is no shortcut to GSoC selection and there is no shortcut to GSoC completion.

The student stipend (USD $5,500 in 2014) is not paid to students unless they complete a minimum amount of valid code. This means that even if a student did find some shortcut to selection, it is unlikely they would be paid without completing meaningful work.

If you are the right candidate for GSoC, you will not need a shortcut anyway. Are you the sort of person who can't leave a coding problem until you really feel it is fixed, even if you keep going all night? Have you ever woken up in the night with a dream about writing code still in your head? Do you become irritated by tedious or repetitive tasks and often think of ways to write code to eliminate such tasks? Does your family get cross with you because you take your laptop to Christmas dinner or some other significant occasion and start coding? If some of these statements summarize the way you think or feel you are probably a natural fit for GSoC.

An opportunity money can't buy

The GSoC stipend will not make you rich. It is intended to make sure you have enough money to survive through the summer and focus on your project. Professional developers make this much money in a week in leading business centers like New York, London and Singapore. When you get to that stage in 3-5 years, you will not even be thinking about exactly how much you made during internships.

GSoC gives you an edge over other internships because it involves publicly promoting your work. Many companies still try to hide the potential of their best recruits for fear they will be poached or that they will be able to demand higher salaries. Everything you complete in GSoC is intended to be published and you get full credit for it. Imagine a young musician getting the opportunity to perform on the main stage at a rock festival. This is how the free software community works. It is a meritocracy and there is nobody to hold you back.

Having a portfolio of free software that you have created or collaborated on and a wide network of professional contacts that you develop before, during and after GSoC will continue to pay you back for years to come. While other graduates are being screened through group interviews and testing days run by employers, people with a track record in a free software project often find they go straight to the final interview round.

Register your domain name and make a permanent email address

Free software is all about community and collaboration. Register your own domain name as this will become a focal point for your work and for people to get to know you as you become part of the community.

This is sound advice for anybody working in IT, not just programmers. It gives the impression that you are confident and have a long term interest in a technology career.

Choosing the provider: as a minimum, you want a provider that offers DNS management, static web site hosting, email forwarding and XMPP services all linked to your domain. You do not need to choose the provider that is linked to your internet connection at home and that is often not the best choice anyway. The XMPP foundation maintains a list of providers known to support XMPP.

Create an email address within your domain name. The most basic domain hosting providers will let you forward the email address to a webmail or university email account of your choice. Configure your webmail to send replies using your personalized email address in the From header.

Update your ~/.gitconfig file to use your personalized email address in your Git commits.

Create a web site and blog

Start writing a blog. Host it using your domain name.

Some people blog every day, other people just blog once every two or three months.

Create links from your web site to your other profiles, such as a Github profile page. This helps reinforce the pages/profiles that are genuinely related to you and avoid confusion with the pages of other developers.

Many mentors are keen to see their students writing a weekly report on a blog during GSoC so starting a blog now gives you a head start. Mentors look at blogs during the selection process to try and gain insight into which topics a student is most suitable for.

Create a profile on Github

Github is one of the most widely used software development web sites. Github makes it quick and easy for you to publish your work and collaborate on the work of other people. Create an account today and get in the habbit of forking other projects, improving them, committing your changes and pushing the work back into your Github account.

Github will quickly build a profile of your commits and this allows mentors to see and understand your interests and your strengths.

In your Github profile, add a link to your web site/blog and make sure the email address you are using for Git commits (in the ~/.gitconfig file) is based on your personal domain.

Start using PGP

Pretty Good Privacy (PGP) is the industry standard in protecting your identity online. All serious free software projects use PGP to sign tags in Git, to sign official emails and to sign official release files.

The most common way to start using PGP is with the GnuPG (GNU Privacy Guard) utility. It is installed by the package manager on most Linux systems.

When you create your own PGP key, use the email address involving your domain name. This is the most permanent and stable solution.

Print your key fingerprint using the gpg-key2ps command, it is in the signing-party package on most Linux systems. Keep copies of the fingerprint slips with you.

This is what my own PGP fingerprint slip looks like. You can also print the key fingerprint on a business card for a more professional look.

Using PGP, it is recommend that you sign any important messages you send but you do not have to encrypt the messages you send, especially if some of the people you send messages to (like family and friends) do not yet have the PGP software to decrypt them.

If using the Thunderbird (Icedove) email client from Mozilla, you can easily send signed messages and validate the messages you receive using the Enigmail plugin.

Get your PGP key signed

Once you have a PGP key, you will need to find other developers to sign it. For people I mentor personally in GSoC, I'm keen to see that you try and find another Debian Developer in your area to sign your key as early as possible.

Free software events

Try and find all the free software events in your area in the months between now and the end of the next Google Summer of Code season. Aim to attend at least two of them before GSoC.

Look closely at the schedules and find out about the individual speakers, the companies and the free software projects that are participating. For events that span more than one day, find out about the dinners, pub nights and other social parts of the event.

Try and identify people who will attend the event who have been GSoC mentors or who intend to be. Contact them before the event, if you are keen to work on something in their domain they may be able to make time to discuss it with you in person.

Take your PGP fingerprint slips. Even if you don't participate in a formal key-signing party at the event, you will still find some developers to sign your PGP key individually. You must take a photo ID document (such as your passport) for the other developer to check the name on your fingerprint but you do not give them a copy of the ID document.

Events come in all shapes and sizes. FOSDEM is an example of one of the bigger events in Europe, is a similarly large event in Australia. There are many, many more local events such as the Debian UK mini-DebConf in Cambridge, November 2015. Many events are either free or free for students but please check carefully if there is a requirement to register before attending.

On your blog, discuss which events you are attending and which sessions interest you. Write a blog during or after the event too, including photos.

Quantcast generously hosted the Ganglia community meeting in San Francisco, October 2013. We had a wild time in their offices with mini-scooters, burgers, beers and the Ganglia book. That's me on the pink mini-scooter and Bernard Li, one of the other Ganglia GSoC 2014 admins is on the right.

Install Linux

GSoC is fundamentally about free software. Linux is to free software what a tree is to the forest. Using Linux every day on your personal computer dramatically increases your ability to interact with the free software community and increases the number of potential GSoC projects that you can participate in.

This is not to say that people using Mac OS or Windows are unwelcome. I have worked with some great developers who were not Linux users. Linux gives you an edge though and the best time to gain that edge is now, while you are a student and well before you apply for GSoC.

If you must run Windows for some applications used in your course, it will run just fine in a virtual machine using Virtual Box, a free software solution for desktop virtualization. Use Linux as the primary operating system.

Here are links to download ISO DVD (and CD) images for some of the main Linux distributions:

If you are nervous about getting started with Linux, install it on a spare PC or in a virtual machine before you install it on your main PC or laptop. Linux is much less demanding on the hardware than Windows so you can easily run it on a machine that is 5-10 years old. Having just 4GB of RAM and 20GB of hard disk is usually more than enough for a basic graphical desktop environment although having better hardware makes it faster.

Your experiences installing and running Linux, especially if it requires some special effort to make it work with some of your hardware, make interesting topics for your blog.

Decide which technologies you know best

Personally, I have mentored students working with C, C++, Java, Python and JavaScript/HTML5.

In a GSoC program, you will typically do most of your work in just one of these languages.

From the outset, decide which language you will focus on and do everything you can to improve your competence with that language. For example, if you have already used Java in most of your course, plan on using Java in GSoC and make sure you read Effective Java (2nd Edition) by Joshua Bloch.

Decide which themes appeal to you

Find a topic that has long-term appeal for you. Maybe the topic relates to your course or maybe you already know what type of company you would like to work in.

Here is a list of some topics and some of the relevant software projects:

  • System administration, servers and networking: consider projects involving monitoring, automation, packaging. Ganglia is a great community to get involved with and you will encounter the Ganglia software in many large companies and academic/research networks. Contributing to a Linux distribution like Debian or Fedora packaging is another great way to get into system administration.
  • Desktop and user interface: consider projects involving window managers and desktop tools or adding to the user interface of just about any other software.
  • Big data and data science: this can apply to just about any other theme. For example, data science techniques are frequently used now to improve system administration.
  • Business and accounting: consider accounting, CRM and ERP software.
  • Finance and trading: consider projects like R, market data software like OpenMAMA and connectivity software (Apache Camel)
  • Real-time communication (RTC), VoIP, webcam and chat: look at the JSCommunicator or the Jitsi project
  • Web (JavaScript, HTML5): look at the JSCommunicator

Before the GSoC application process begins, you should aim to learn as much as possible about the theme you prefer and also gain practical experience using the software relating to that theme. For example, if you are attracted to the business and accounting theme, install the PostBooks suite and get to know it. Maybe you know somebody who runs a small business: help them to upgrade to PostBooks and use it to prepare some reports.

Make something

Make some small project, less than two week's work, to demonstrate your skills. It is important to make something that somebody will use for a practical purpose, this will help you gain experience communicating with other users through Github.

For an example, see the servlet Juliana Louback created for fixing phone numbers in December 2013. It has since been used as part of the Lumicall web site and Juliana was selected for a GSoC 2014 project with Debian.

There is no better way to demonstrate to a prospective mentor that you are ready for GSoC than by completing and publishing some small project like this yourself. If you don't have any immediate project ideas, many developers will also be able to give you tips on small projects like this that you can attempt, just come and ask us on one of the mailing lists.

Ideally, the project will be something that you would use anyway even if you do not end up participating in GSoC. Such projects are the most motivating and rewarding and usually end up becoming an example of your best work. To continue the example of somebody with a preference for business and accounting software, a small project you might create is a plugin or extension for PostBooks.

Getting to know prospective mentors

Many web sites provide useful information about the developers who contribute to free software projects. Some of these developers may be willing to be a GSoC mentor.

For example, look through some of the following:

Getting on the mentor's shortlist

Once you have identified projects that are interesting to you and developers who work on those projects, it is important to get yourself on the developer's shortlist.

Basically, the shortlist is a list of all students who the developer believes can complete the project. If I feel that a student is unlikely to complete a project or if I don't have enough information to judge a student's probability of success, that student will not be on my shortlist.

If I don't have any student on my shortlist, then a project will not go ahead at all. If there are multiple students on the shortlist, then I will be looking more closely at each of them to try and work out who is the best match.

One way to get a developer's attention is to look at bug reports they have created. Github makes it easy to see complaints or bug reports they have made about their own projects or other projects they depend on. Another way to do this is to search through their code for strings like FIXME and TODO. Projects with standalone bug trackers like the Debian bug tracker also provide an easy way to search for bug reports that a specific person has created or commented on.

Once you find some relevant bug reports, email the developer. Ask if anybody else is working on those issues. Try and start with an issue that is particularly easy and where the solution is interesting for you. This will help you learn to compile and test the program before you try to fix any more complicated bugs. It may even be something you can work on as part of your academic program.

Find successful projects from the previous year

Contact organizations and ask them which GSoC projects were most successful. In many organizations, you can find the past students' project plans and their final reports published on the web. Read through the plans submitted by the students who were chosen. Then read through the final reports by the same students and see how they compare to the original plans.

Start building your project proposal now

Don't wait for the application period to begin. Start writing a project proposal now.

When writing a proposal, it is important to include several things:

  • Think big: what is the goal at the end of the project? Does your work help the greater good in some way, such as increasing the market share of Linux on the desktop?
  • Details: what are specific challenges? What tools will you use?
  • Time management: what will you do each week? Are there weeks where you will not work on GSoC due to vacation or other events? These things are permitted but they must be in your plan if you know them in advance. If an accident or death in the family cut a week out of your GSoC project, which work would you skip and would your project still be useful without that? Having two weeks of flexible time in your plan makes it more resilient against interruptions.
  • Communication: are you on mailing lists, IRC and XMPP chat? Will you make a weekly report on your blog?
  • Users: who will benefit from your work?
  • Testing: who will test and validate your work throughout the project? Ideally, this should involve more than just the mentor.

If your project plan is good enough, could you put it on Kickstarter or another crowdfunding site? This is a good test of whether or not a project is going to be supported by a GSoC mentor.

Learn about packaging and distributing software

Packaging is a vital part of the free software lifecycle. It is very easy to upload a project to Github but it takes more effort to have it become an official package in systems like Debian, Fedora and Ubuntu.

Packaging and the communities around Linux distributions help you reach out to users of your software and get valuable feedback and new contributors. This boosts the impact of your work.

To start with, you may want to help the maintainer of an existing package. Debian packaging teams are existing communities that work in a team and welcome new contributors. The Debian Mentors initiative is another great starting place. In the Fedora world, the place to start may be in one of the Special Interest Groups (SIGs).

Think from the mentor's perspective

After the application deadline, mentors have just 2 or 3 weeks to choose the students. This is actually not a lot of time to be certain if a particular student is capable of completing a project. If the student has a published history of free software activity, the mentor feels a lot more confident about choosing the student.

Some mentors have more than one good student while other mentors receive no applications from capable students. In this situation, it is very common for mentors to send each other details of students who may be suitable. Once again, if a student has a good Github profile and a blog, it is much easier for mentors to try and match that student with another project.

GSoC logo generic


Getting into the world of software engineering is much like joining any other profession or even joining a new hobby or sporting activity. If you run, you probably have various types of shoe and a running watch and you may even spend a couple of nights at the track each week. If you enjoy playing a musical instrument, you probably have a collection of sheet music, accessories for your instrument and you may even aspire to build a recording studio in your garage (or you probably know somebody else who already did that).

The things listed on this page will not just help you walk the walk and talk the talk of a software developer, they will put you on a track to being one of the leaders. If you look over the profiles of other software developers on the Internet, you will find they are doing most of the things on this page already. Even if you are not selected for GSoC at all or decide not to apply, working through the steps on this page will help you clarify your own ideas about your career and help you make new friends in the software engineering community.

Will Kahn-GreeneInput: Trigger rule project Phase 1


Last quarter, I finished up the suggester framework for Input. When a user leaves feedback, registered suggester modules would look at the feedback metadata and text and return suggested links. The suggested links would then show up on the Thank You page. Users could then read a bit about the link and click on it if it was appealing.

The first suggester I wrote does a search against SUMO kb articles to see if any of the kb articles seemed relevant to the feedback. Users frequently leave feedback about problems they're having that could be known issues with known solutions or even problems Firefox solves with features the user wasn't aware of. Because of this, it behooves us greatly to guide these users to the solutions that make their Firefox experience better. I wrote a post about that.

This project covers adding a new suggester that allows analyzers to set up trigger rules for suggestions which is stored in the database. When feedback matches the criteria for a trigger rule, then the suggestion is shown.

I pushed out the last code changes on September 9th, 2015. On September 25th, we created a trigger rule for feedback talking about Norton's addon and suggested a link for a SUMO kb article that talks about the problem. In the 5 days, 22 people saw the suggestion and 6 clicked on the link.

This blog post is a write-up for the Trigger rule project phase 1.

Read more… (10 mins to read)

Support.Mozilla.OrgWhat’s up with SUMO – 2nd October

What have you been up to this week, SUMO warriors? We have some news and announcements for you, so start reading before the weekend sweeps us all away from our screens!

Welcome, New Contributors!

If you joined us recently, don’t hesitate – come over and say “hi” in the forums!
Don’t forget that if you are new to SUMO and someone helped you get started in a nice way you can nominate them for the Buddy of the Month!

Contributors of the week

  • A group nomination to all the people who keep being awesome and supporting millions of users around the world :-) If you are reading these words… this most likely means YOU!

Last SUMO Community meeting

Reminder: the next SUMO Community meeting…

  • …is going to take place on Monday,5th of October. Join us!
  • If you want to add a discussion topic to upcoming the live meeting agenda:
    • Start a thread in the Community Forums, so that everyone in the community can see what will be discussed and voice their opinion here before Monday (this will make it easier to have an efficient meeting).
    • Please do so as soon as you can before the meeting, so that people have time to read, think, and reply (and also add it to the agenda).



Support Forum

  • Some details from the last SUMO Day:
    • 45 participants: 32 for Firefox, 5 for Firefox for Android, 2 for Firefox for iOS
    • 93% issues replied to in 24 hours, 96% in 72 hours (FF, FF OS and FF iOS)
    • 37% issues replied to in 24 hours and 87% in 72 hours for FF for Android
    • Once again – HUGE thanks to all participants! You rock!
  • Save the date: the next SUMO Questions Day is coming up on the 8th of October.

Knowledge Base

  • The tracking protection articles will be revised and finalized by mid-October, depending on the coordination with Legal and Product teams.
  • If you want work with us directly on the Knowledge Base as an intern, take a look at this Outreachy opportunity.


  • (for Android) The documentation for version 42 has started, and a dot release for 41 took place as well.
  • (for Desktop) Version 41 has landed! Head over to our forums to learn more and discuss.
    • There has been a general increase in the number of browser hanging cases, so expect to see users reporting problems of that type. Yes, Farmville 2 is unfortunately affected, as well.
That’s all for now. May you have a great weekend! We all hope to see you refreshed, rested, and relaxed on Monday.
P.S. Don’t forget that we’re on Twitter… where we recently passed the 500 follower mark! Thank you!

Mark FinkleFun With Telemetry: URL Suggestions

Firefox for Android has a UI Telemetry system. Here is an example of one of the ways we use it.

As you type a URL into Firefox for Android, matches from your browsing history are shown. We also display search suggestions from the default search provider. We also recently added support for displaying matches to previously entered search history. If any of these are tapped, with one exception, the term is used to load a search results page via the default search provider. If the term looks like a domain or URL, Firefox skips the search results page and loads the URL directly.


  1. This suggestion is not really a suggestion. It’s what you have typed. Tagged as user.
  2. This is a suggestion from the search engine. There can be several search suggestions returned and displayed. Tagged as engine.#
  3. This is a special search engine suggestion. It matches a domain, and if tapped, Firefox loads the URL directly. No search results page. Tagged as url
  4. This is a matching search term from your search history. There can be several search history suggestions returned and displayed. Tagged as history.#

Since we only recently added the support for search history, we want to look at how it’s being used. Below is a filtered view of the URL suggestion section of our UI Telemetry dashboard. Looks like history.# is starting to get some usage, and following a similar trend to engine.# where the first suggestion returned is used more than the subsequent items.

Also worth pointing out that we do get a non-trivial amount of url situations. This should be expected. Most search keyword data released by Google show that navigational keywords are the most heavily used keywords.

An interesting observation is how often people use the user suggestion. Remember, this is not actually a suggestion. It’s what the person has already typed. Pressing “Enter” or “Go” would result in the same outcome. One theory for the high usage of that suggestion is it provides a clear outcome: Firefox will search for this term. Other ways of trigger the search might be more ambiguous.


Yunier José Sosa VázquezPablo Pérez: “Mozilla seguirá velando por los derechos de los usuarios en Internet”

Pablo-Pérez Diez-Mozilla-HispanoPara conocer mucho más acerca de las personas que integran Mozilla Hispano, llegan nuevamente las entrevistas los miembros de la comunidad. Este espacio servirá para reconocer el trabajo de nuestros colaboradores.

En esta oportunidad tenemos como invitado al español Pablo Pérez.

¿Cómo te llamas y a qué te dedicas?
Me llamo Pablo Pérez Diez, nací en un pueblo del norte de España. Posteriormente me trasladé a la ciudad de Valladolid (también en el norte de España) para realizar mis estudios de Técnico Superior en Telemática e Ingeniero Técnico en Telemática. Tras unos años trabajando como programador allí, actualmente resido en Madrid.

¿Por qué te decidiste a colaborar con Mozilla?
Decidí colaborar para aportar mi grano de arena en la defensa de los derechos de los usuarios online (neutralidad, privacidad, derecho al olvido, etc.), todos ellos cada vez más en peligro.

¿Actualmente qué labor desempeñas en la Comunidad?
Actualmente realizo las tareas de coordinación en el área de asistencia que integra tanto el foro como Twitter.

¿Qué es lo que más valoras o es lo más positivo de Mozilla / la Comunidad?
Lo que más valoro es como gente de diferentes países, creencias, ideologías, etc. son capaces de colaborar por un objetivo común que en última instancia es el bien común.

¿Qué te aporta a ti Mozilla / la Comunidad?
Me aporta la experiencia de colaborar con otra mucha gente aprendiendo lo mejor de todos ellos tanto de países hispanohablantes como de otros muchos más.

¿Como crees que será Mozilla en el futuro?
En mi opinión Mozilla seguirá velando por los derechos de los usuarios en Internet apoyándose cada vez más en la comunidad.

Unas palabras para las personas que desean unirse a la Comunidad.
Si compartes los valores tanto de Mozilla como de Mozilla Hispano este es el lugar perfecto para contribuir a que esos valores sean respetados y obteniendo grandes experiencias con el resto de la comunidad.

Muchas gracias Pablo por acceder a la entrevista.

Fuente: Mozilla Hispano

Air MozillaWebmaker Demos Oct 2 2015

Webmaker Demos Oct 2 2015 Webmaker Demos Friday October 2 2015

Hal Wineduo MFA & viscosity no-cell setup

duo MFA & viscosity no-cell setup

The Duo application is nice if you have a supported mobile device, and it’s usable even when you you have no cell connection via TOTP. However, getting Viscosity to allow both choices took some work for me.

For various reasons, I don’t want to always use the Duo application, so would like for Viscosity to alway prompt for password. (I had already saved a password - a fresh install likely would not have that issue.) That took a bit of work, and some web searches.

  1. Disable any saved passwords for Viscosity. On a Mac, this means opening up “Keychain Access” application, searching for “Viscosity” and deleting any associated entries.

  2. Ask Viscosity to save the “user name” field (optional). I really don’t need this, as my setup uses a certificate to identify me. So it doesn’t matter what I type in the field. But, I like hints, so I told Viscosity to save just the user name field:

    defaults write com.viscosityvpn.Viscosity RememberUsername -bool true

With the above, you’ll be prompted every time. You have to put “something” in the user name field, so I chose to put “push or TOTP” to remind me of the valid values. You can put anything there, just do not check the “Remember details in my Keychain” toggle.