posts categorized as “add-ons”

Add-ons in 2011

This weekend we said goodbye to an action-packed year, and I thought it’d be fun to think back on all we accomplished in Add-ons in 2011.

Firefox 4 Shipped

A critical release for many reasons, Firefox 4 introduced a completely rewritten and redesigned Add-ons Manager, including the interactive discovery pane (“Get Add-ons”), automatic add-on updates, and addressed the single biggest complaint for years with add-ons: installation without restarting. Firefox 4 also allowed us to see how many users actually use add-ons, how many non-hosted add-ons are out there, and gather real-world performance data — all things for which we had no insights before Firefox 4.

The discovery pane was viewed more than 5 million times in the 24 hours after release, and is currently viewed between 2.7 and 2.9 million times each day. It’s responsible for 40,000 add-on downloads every day, plus the 300,000 downloads that come from the Add-ons Manager search. 33% of new add-ons submitted to AMO each month are restartless.

New Developer Tools, Editor Tools, and Review Process

It seems like this happened much more than a year ago, but it was in early 2011 that we launched our brand new Developer Tools on AMO — in my opinion, the best management tools for add-ons, apps, or anything like it on the web. In 2010 we made the decision to rearchitect our review process to require all add-ons to be reviewed and get rid of the sandbox with 7,000 unreviewed add-ons in it. We launched that new process in 2011 by introducing preliminary reviews and direct links while waiting for review. And we made a number of awesome improvements to our Editor tools and statistics dashboard.

Towards the end of last year, the need for a faster Firefox release cycle was apparent, and nearly every team at Mozilla began preparing for the major changes afoot. Add-on compatibility has always been a huge barrier to releasing more often, so it was critical we have a plan that wouldn’t leave add-ons or users behind. With previous releases usually a year or more apart, we could begin compatibility outreach to developers 3 months in advance of the release, and were able to get at least 80% of the most-used Mozilla-hosted add-ons compatible with the new version. For this new system to work, we wanted a compatibility process that didn’t require developers to lift a finger unless their add-on was one of the few broken.

Firefox assumes that add-ons are incompatible from one version to the next because, in previous versions, they often were. This becomes a big problem when nearly all add-ons actually are compatible in our shorter release cycles. We devised a plan to work around the assumed incompatibility that had three parts:

  • Firefox developers should consider the add-on compatibility impact of every change they make
  • Firefox developers should follow a compatibility notification process to ensure we communicate changes to add-on developers
  • AMO ( will scan hosted add-ons for issues with the new Firefox version and automatically bump their compatibility if none are found

Longer term, the Add-on SDK lets developers build restartless add-ons without worrying about compatibility hassles.

AMO has made huge improvements in nearly every way since I started working on it in 2006 — design, scalability, performance, user experience, content, quality. Back then, we had a whopping 6 listed add-ons on our homepage: one featured promo block and a list of the top 5 downloads that week. None could be installed without going to the add-on’s details page first.

In contrast, today there are dozens of add-ons on the homepage and most can be installed without leaving the page. When we set out to design the new homepage, we wanted to surface more add-ons in such a way that every user would be able to see something interesting, read the details, and grab it without leaving the page. We wanted it to be easy to scan through the page and if you weren’t interested in a particular add-on, it wouldn’t take any time to skim right over it.

We knew we’d probably use a hover effect to expose the additional details, but wanted to steer clear of the bad hover interactions used on many popular websites and similar galleries today. Chris Howse and I whiteboarded some mocks of an early hover interaction of a card, and began examining the ways it was insufficient. Most hover designs block scanning in one of the directions you’re trying to go (down or to the right) or, in order to avoid that, display content above and break your downward focus.

Add-on-Con party chalk boardLast Wednesday and Thursday I spoke for the third year at Add-on-Con. This year’s conference was notably different from the rest for a number of reasons, the biggest being a focus on apps. It certainly gave me a lot to think about, and hopefully I’ll have time to blog some of my thoughts on the topic of add-ons vs. apps.

Wednesday night’s Mozilla Social was a blast, so thanks to everyone who attended! And a huge thanks to the many people at Mozilla who were involved in our participation at Add-on-Con this year: Grace, Sara, Mayumi, Dan, Caitlin, William, Mary, Jane, and of course to our speakers Myk, Mark, Jorge, Boriss, Dave, and Jay.

Many people have already asked for my slides from my various talks, so here they are:

So much has changed since the last Add-on-Con and 2011 is already promising to be a very exciting time for add-ons, so I can only imagine what themes will surface at next year’s conference.

This Wednesday and Thursday, the Computer History Museum in Mountain View will be overrun with add-on developers eager to learn, collaborate, and network at this year’s Add-on-Con. I’ll be speaking at a number of sessions for the third year, and am looking forward to seeing familiar faces and first-time attendees.

If you’ll be attending (or even if you aren’t), be sure to join us after the first day’s training sessions for the Mozilla social from 5 – 9pm. Learn more and RSVP here.