Mozilla: No, Firefox XUL add-ons are not an endangered species

Last May, Aza Raskin and the team at Mozilla Labs introduced Jetpack, essentially an extensibility model for the organization's Firefox browser that enables new JavaScript apps to modify the functionality of the browser on the fly. The goal is that anyone who could create a Web page could use exactly the same tools (HTML, CSS, and ordinary JavaScript, plus the appropriate APIs) to build a Firefox add-on. Now on version 0.7, Jetpack is slowly gaining momentum.

But where will that momentum lead? Is Mozilla seriously considering the Jetpack development model as an eventual replacement for XUL (XML User Interface language, pronounced "zool" like the refrigerator-based creature from Ghostbusters)? That was the question ZDNet blogger Adrian Kingsley-Hughes asked earlier this week, in a blog post entitled, "Is Mozilla preparing to ditch add-ons as we know them?"

"Extensions are powerful stuff," Kingsley-Hughes wrote, "but Mozilla is working on a project that could see add-ons as we know them disappear."

In fairness, Kingsley-Hughes' post was not really all that alarmist; it was a thoughtful discussion of the benefits and pitfalls of a possible evolutionary course for Firefox. But it did prompt Mozilla to post a response, apparently directed towards the community of Firefox add-on developers who comprise one of that browser's most unique and competitive assets.

"There's been a lot of speculation over the past couple of days around the future of Firefox Add-ons, and how Jetpack fits into that future. There's currently a lot of misinformation swirling about this topic and it's making people very unhappy," read the company's first official response to the subject. But as it continued, it contained the following: "Right now, you write a Firefox extension; in the future you'll be able to write an extension using Jetpack. If Jetpack doesn't provide the flexibility or feature you need, you'll be able to contribute it in true Mozilla fashion."

That could perhaps have been phrased better, since you can actually write a Jetpack extension (using version 0.7) now. And if Jetpack isn't what a developer wants, just what do we presume "true Mozilla fashion" to be?
Those questions were addressed by a blog post directly from the Add-ons Team, as opposed to Mozilla Labs -- in other words, from the folks responsible for what's included in today's stable browser, rather than what's not officially stable that can be added on.

"We want to assure everyone in our community that XUL-based add-ons are not going anywhere in the foreseeable future. Mozilla is committed to keeping Firefox the most customizable browser, and add-ons are here to stay," reads the Add-on Team's official response. "Without our add-ons community, Firefox would not be the most extended browser in existence, and we owe them an enormous debt of gratitude for getting us to where we are today."

Jetpack is not being considered as a "complete" replacement for XUL, the post continued, although the phraseology does appear to leave open a crack in the door.