Jan 12

Bringing Android Native Firefox to Beta

I like trains. Last year, we put Firefox on a train-based release model: every six weeks, another train leaves the station. When a feature catches the train it moves through iterative testing on our Nightly, Aurora and Beta channels and, if that testing confirms its stability and general excellence, it goes out to hundreds of millions of Firefox users. If testing reveals an issue, we pull the feature out for another round of review, and let it catch a later train. The trains have run on time ever since, and the results have been incredible. Firefox improvements reach our users regularly, faster than ever before.

However, when we decided to rebuild Firefox for Android using Native UI, we recognized that the first release couldn’t ride the trains. The iterative release model that serves us so well with Firefox works best when most changes are incremental and independent. Building a new high-performance front end for Firefox on Android, by contrast, involves many interconnected pieces being rebuilt in tandem.

Right now, the engineering team is focused on building an amazing browser for Android phones, and we’ll have a beta to show you in the coming weeks. It might coincide with one of our regular 6 week trains, but it’s quite possible it won’t. If it doesn’t, don’t worry. It’s cool. Firefox for Android will get back on the trains once the native UI rebuild is finished, but for a change this major we have extra work we want to do before we send it out the door. We’ll only ship it once we’re happy with its quality and performance. If you can’t wait that long, check us out on tablets or try our early release Aurora builds. I think you’ll be pleased.

[This post originally appeared on the Future of Firefox blog]

Aug 11


[This is a re-post of a post that originally appeared on the Future of Firefox blog]

Last week we released a new version of Firefox. We shipped on time, 6 weeks after the last update, making it our first true rapid release milestone. There was cake. Now that we know that we’re capable of this velocity, I’d like to revisit the reasons why it’s important, and the lessons we’ve already learned.

Mission drives Mozilla. People sometimes forget that we’re a non-profit, that our only job is to make the Web a better place. Rapid release advances our mission in important ways. We get features and improvements to users faster. We get new APIs and standards out to web developers faster. We are delivering on the promise of the web at web speed.

Small, frequent releases improve quality, too. Engineers in the Mozilla community regularly say things now like “I don’t like not understanding this piece, let’s back it out and I’ll catch the next train.” We move deliberately. We don’t rush. And, even though it sounds like a contradiction, when we take our time we go faster.

There’s a great deal for us to be proud of, but we also need to be humble. This change was hard for us to make, and it’s been hard for some of our supporters, too. We have been glib or dismissive in the way we’ve communicated about parts of it. We live rapid release daily, and that makes it easier for us to see past the problems. We are also tenacious about the necessity of our new schedule, and tenacity can be mistaken for obstinacy.

We, everyone in the Mozilla community, all of us, need to communicate with clarity and sensitivity. We need to help the people who support our mission to understand why these changes are essential. We need to keep listening, and adjusting as we learn. We need to, and we will.

The push to ship faster isn’t some kind of software machismo. We push ourselves to ship faster because the web is under threat. Amazing and innovative people are doing amazing and innovative things and right now they have a choice: build for the web, or build for the walled gardens. The web can win that fight.

The open web is the most amazing, universal communication and distribution platform ever built. To win, the web needs to be agile and responsive. To help it, we need to be agile and responsive, too. That’s why rapid release matters.

Jul 11

Every Six Weeks

It’s astounding to me, but we’ve been living rapid release for a few months now. We’re moving faster. A new feature implemented today and landed on mozilla-central can be delivered to our users in 12 to 18 weeks, not months or years. Incredibly, the same process that gives us that agility is giving us greater robustness, too. Testing and stabilization of each release across progressively larger audiences helps us find and fix bugs early, and build confidence in the quality of each release.

I want to clarify an important part of the process, though, that I think many people haven’t yet understood. Remember, an individual release train is 6 weeks of development time followed by 12 weeks of stabilization:

New work doesn’t land on Aurora and Beta. Instead, those channels focus exclusively on working with our heroic and growing community of testers to spot any unexpected issues introduced during development, and then resolve them. Looking at this diagram, you might well conclude that we’d have a release ready every 18 weeks.

Aurora and Beta are so single-minded in their focus on stabilization and testing, though, that many engineers can move on to new work. If we take a step back and look at the broader picture, this is what actually happens:

During the 12 weeks that a release spends on Aurora and Beta, the Mozilla community is not sitting idle. They are already working on features and fixes for the next release, and the release after that. Every 6 weeks their work is picked up into the next Aurora, the next Beta, and the next release. When you look at this broader picture, you notice an important point:

There can be a new release of Firefox every 6 weeks, not every 12 or 18.

I’ll say it again, because it’s important: most of the time, we’ll release a new Firefox every 6 weeks.

Many people are surprised by this fact, though it’s been part of the process all along. When Firefox 4 came out, we committed to ship the next release of Firefox within 3 months. We did it, and when we did I think many people concluded that we have moved to a 3 month cycle. In truth, though, the only reason it took us 3 months was that our Aurora and Beta channels started off empty; they had to wait for the new release to make it through the process. The next Firefox is already in Beta, and is scheduled to come out 6 weeks after the last one. When that happens, yet another Firefox will enter Beta, and so on.

We’re studying the effects of the process carefully; it’s a big change and we will be flexible in our approach as new information comes in. We may decide that 6 weeks is the wrong interval, for instance, though it’s worth remembering that Firefox maintenance releases have been released on 6-8 week intervals for years, and sometimes included major changes. We’re also paying close attention to the impacts this cycle has on our ecosystem of add-ons, plugins, and other 3rd party software that interacts with Firefox. We’re working with large organizations, too, to understand how rapid release can fit into their software deployment systems.

Whatever adjustments we make, it’s clear that rapid release is a major improvement in our ability to respond to the needs of our users and the web. Every 6 weeks we have a new Firefox to evaluate and, unless some surprising and irreconcilable breakage is discovered, release to the world. No one will have to wait a year for the developer scratchpad now in Beta, or the massive memory and performance improvements already on Aurora, or the slick tab management animations soon to land on Nightly. Rapid release is already paying dividends, and we’re just getting started.

[This post originally appeared on the Channels blog]

Apr 11


a team in a rowboat on blue water
The Firefox community is kicking ass. We just worked through our first Aurora merge as part of our new rapid release process and in less than 6 weeks, the next train leaves the station. We are rewriting the way we build software and we are doing it fast.

We’re succeeding because we’re acting deliberately. We’re doing it on purpose. We know what we need our release process to do and we’re building forward from that, instead of shooting first and calling whatever we hit the target.

I’m glad that we’re being deliberate about how we build Firefox. We need to be deliberate about what we build, too. I’ll tell you how I think that should go, after a brief digression on how it has gone up until now.

(If you have no time for that, deb’s written a more concise introduction.)

Continue reading →

Feb 11


Beltzner’s moving on.

When someone leaves the Mozilla Corp, it’s tradition for them to send a note to our global alias saying so. Mike sent his late last week, and this was my reply.

Continue reading →

Feb 11

Vacuums and You (or, Estimating Like an Astronaut)

I’m going to teach you a surprisingly effective trick for estimating better, but first I need to talk about dressing up vacuum cleaners.

Ze Frank is a pretty creative guy, but what makes him really interesting to me is his ability to make other people creative. It’s what he does. He catalyzes creativity, frequently among those who don’t consider themselves creative. And when he talks about how he does it, he talks about the value of constraint.

Asked to go and “be creative,” he notes, most people shut down. So, instead, he asks for something more specific. He asked them to make a whole earth sandwich; they made a few. He asked people to send in pictures of vacuum cleaners dressed as people. He got 215. Constraining people, forcing them to solve a smaller problem, made them better at it.

Creativity isn’t the only thing that benefits from constraint. Asking engineers (or, really, anyone) for “an estimate” is basically akin to asking them to “be creative.” They know what examples of the thing in question look like, they understand that it’s a reasonable request, they just don’t actually know how to get there from here, much less how to be accurate about it.

Back in the sixties, NASA and the US DoD were spending a great deal of money on engineering. They therefore took a keen interest in improving planning and estimation, not unlike the interest you might take if someone was setting all of your money on fire. Out of this interest sprung the mellifluously titled “PERT/COST SYSTEMS DESIGN” which, on the subject of estimation, made this central observation:

If you ask engineers for 3 estimates (Best Case, Most Likely, Worst Case) instead of 1, you get different answers.

That’s pretty exciting! Constraints get us different answers, and different answers mean more bits of information. If you’re not convinced that this is brilliant, though, here comes some next level awesome: A (weighted) average of these 3 estimates is a better predictor of actual completion time than any one of them. Specifically

(Best + 4*Most Likely + Worst) / 6

turns out to work pretty well in the general case. These so-called “PERT Estimates” or “3-point Estimates” give engineers credit for their assessment of “most likely” by weighting it heavily, but still allow optimism and pessimism to pull the average. I dare you to argue with this graph:

Likelihood of project completion date vs estimates (Science, bitches!)

Likelihood of project completion date vs estimates

Having 3 data points actually helps in other ways, too. It means you can more clearly quantify the uncertainty of a project by comparing best and worst case estimates, and watching to see if the distance between them shrinks over time. It means you can produce “optimistic” and “pessimistic” schedules. And, most importantly, it means that everyone is saying the same thing when they estimate.

Best, Worst, Most Likely. Try it for your next project, and see how it works. As we finish Firefox 4 and start looking at what comes next, there will be plenty of estimation happening, and I’m keen to see us bringing more science to the table. This may not be the right model for us, or we may discover that the coefficients need changing in our version of the equation; that’s fine. That would actually be a great result. My interest isn’t in pushing a particular tool, my interest is in getting better at planning, getting more awesome out to our users faster. I think we do that by looking for systems that have worked for others, and seeing how well they adapt to us.

And then we dress up the vacuum cleaners.

Jan 11

Automatic Date Links in MediaWiki

I had time between 1:1s today to solve a wiki problem that’s been nagging me. My codes, let me show you them.

Problem: We have meetings.

What’s worse, we persist in having them every week. Being the kind of project we are, we keep agendas and notes from those meetings publicly and invite the community to participate (does your browser? Great!)

What you want, then, is for each week’s meeting notes to link to next week’s and last week’s, like such:

And so, we do. But those links have to be hand-edited every week. Indeed, the pages for various meeting notes have earnest, heart-wrenching pleas in HTML comments, like

<!– REPLACE YYYY-MM-DD with the previous and next week’s year-month-date –>

No one should have to live like that.

Solution: ParserFunctions

Our mediawiki install includes the ParserFunctions extension, which has a whole bag of tricks. One of these tricks is {{#time}}. #time lets you produce various kinds of time/date strings, to wit:

{{#time: Y-m-d }}

Particularly nice, though, is that you can specify relative times, e.g.

{{#time: Y-m-d|+1 week}}

The relative syntax is so flexible, in fact, that I can utter this monstrosity:

[[Platform/{{#time: Y-m-d|tuesday last week}}|« previous week]]

to link to last week’s notes from a given page!

Still with me? Because there’s one snag left. The above works for people who have a static front page with this week’s info, and only ever want to link one week back. But those relative dates are relative to now — what if I want each link in the chain to link to the week prior?

No problem — our pages are named according to their dates, so just make the link relative to that, instead:

[[Platform/{{#time: Y-m-d | {{SUBPAGENAME}} -1 week}}|« previous week]]


The things you learn while waiting for a phone call. If you want to get really exciting, you can do all this in transclusion tags, to have last week’s notes automatically added to this week, but that’s left as a terrifyingly-recursive exercise for the reader.

What’s your favourite mediawiki hack?

(PS – Full credit to Melissa for giving me the idea in the first place. I am naught but the implementor.)

Jan 11

It’s Almost Ready

Shipping great software to lots of people is hard. At Mozilla we talk about shipping only “when it’s ready,” and the devotion our community has to Firefox users, and to shipping them a high quality product, is unlike anything I’ve seen elsewhere. We answer to no one but you.

“When it’s ready” doesn’t mean we can take our time, though. Firefox 4 is good for the web, good for our users, and puts the heat on other vendors to up their own game. We need to ship it ASAP – we want release candidates in weeks, not months. And that means a hard look at our blocker list.

Blocker bugs have a rank order. If you can’t have all of them, there are some you’d want more than others, even though every single one of them is a bug we want to fix. That’s healthy. Building software means making those calls. Each bug is evaluated against whether it’s worth holding back the thousands of fixes that have already made it into the Firefox 4 tree. At this point, very few bugs are worth holding back that much awesome.

Hard vs. Soft Blocking1

To that end, then, if you watch bugzilla, you’ve seen blocker bugs sprouting one of two new whiteboard labels:

  • [hardblocker] – These bugs prevent us from shipping. We’ll hold the release for the very last one of them. A hard blocker is a failure of a core part of our release criteria, e.g. a crash, a memory leak, a performance hit, a security issue, a UI breakage that can’t be recovered from, an incompatibility we can’t stomach.
  • [softblocker] – These bugs are things we want to fix as soon as possible, but can ship with if the hard blockers are done. They can be fixed in maintenance releases if needed, or in Firefox 5 which, remember, is not so very far away. Soft blockers might include visual polish, strange edge cases, optional aspects of new specs, or opportunistic performance wins.

Hard blockers trump everything. That doesn’t mean they are the only things that will get fixed – indeed we hope and expect many of our soft blockers to make it in as well. We didn’t clear their blocking flags, they are still legit work items and have landing pre-approval. Soft blockers are what beltzner calls the “opportunity space” – the work that lifts the quality and delight of the product. But we have to make the hard calls, and soft blockers are second priority to shipping. People paid to work on Firefox will be focusing exclusively on hard blockers, first.

The hard blocker list is currently at 143. When it hits 0, we can ship. Let’s kill it dead.

[1] Inevitably, when we do a pass like this, someone will want to digress into a thread about nomenclature. “Why are they blockers if they don’t block?” “Are there hard soft blockers, or soft hard blockers?” I love the creativity of our community, but I think it’s a distraction right now, and I’d suggest to you that we have more interesting problems to solve in the next little while!