Aug 11

18 Months

A Girl and her Pine ConeYou became a little girl.

I wasn’t consulted on this, and if I had been I’m not sure I would have approved. You’re a wonderful little girl. The best little girl. But 6 months ago you just were finishing up with being a baby, and I thought I’d have more time to prepare for the next thing.

Years from now, you’ll want to know all about this part of your life. There’s change everywhere, and you’re not so hot on forming long term memories just yet so you’re counting on your mom and me to take accurate notes. We’re trying. We have a running log that Mommy tries to keep up to date with every new thing you do:

Lily gives lots of kisses now, sometimes when asked, and sometimes spontaneously! She kisses her toys, pages in books, and definitely people.

Lily loves to share things with her toys – they often to get to share her water or her snack. She also likes when we wrap them up in a blanket and rock them to sleep.

Sometimes she likes the water, sometimes she’s really hesitant about it. Mostly she likes to play with the toys on the side of the pool. Life jackets? Forget it.

You literally learn new words daily. Some of my favourites in the last week: Hospital (sounds like hoh-pitatah), aluminum (a-lem-in-nen), tilapia (dala-pala), and dirt (dut).

Your mom and I talk about you a lot. What kind of school you should attend, what kind of activities you might be interested in, what we can do to ensure we both spend as much time with you as possible. We know we can’t predict the future. We know that you’ll have your own opinions, loudly stated. We know that change is constant, and that it can sneak up on you. We do it anyhow, because the illusion of a plan gives us something to hold on to when the uncertainty gets overwhelming. I think you won’t understand this the first time you read it but, when you have kids of your own, you might.

Today you ate a mouthful of sand at the playground.

Today you refused to eat your sandwich until you dipped each torn up little piece into a blob of ketchup.

Today you lay with me on the couch and made me put on music videos and then told me which ones to skip.

Today I have something in my eye.

You became a little girl.

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

1 Year Old

1 Year Old“Da.”

It’s assertive, when I come in the door after work. A statement of fact. “Da has arrived, Mother, in case you were wondering.” And then you squeal, and crawl down off the couch backwards like we taught you, and you crawl over to the gate by the front door and reach up for me to pick you up. And then you remind me where every light in the house is by pointing to them. “Teh.” (pointing) “Teh.”

6 months ago you couldn’t crawl, now you’re starting to walk. 6 months ago you couldn’t talk, now you’re babbling constantly and have 4 or 5 words that are consistent and recognizable, even if they aren’t quite English. 6 months ago you were a baby and now… you’re not.

A lot can happen in 6 months, and a lot has. A lot of firsts, too. Your first tooth, first flight, first foreign country, first beer. Yeah, that’s right, beer. Why? Because you won’t tolerate not having any. Every food that Mommy and Daddy eat, you want; and you’re fearless. Olives, pickles, pizza, steak. You are fearless, in everything, and it scares the crap out of me.

Parents think stupid things, Lily. You’re fascinated with light, will you be a photographer? You love books, will that last, will you read everything you can get your hands on, like Daddy does? You love food now, does that mean you’ll be a foodie, or that you’ll end up flipping a switch and getting really picky? We try to predict the future from the scraps of information we have, because you so constantly surprise and amaze us; we’re desperate for some ability to understand what the future will be like. It’s exciting and scary and foggy and incredible. I don’t want to rush things, but I can’t wait for you to start talking more, because I see the things going on in your head and I want to know all about them.

I asked Grandma when it stops. When each week stops feeling like there’s a brand new kid in the house. Grandma said, “it stops?”

When I write the next one of these, you’ll be 18 months old and, for all I know, you’ll be in college. Go easy on me, Lily. Gently. I love you more than anything in the world, little girl, but it’s all I can do just to keep up.



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!