Now's the time to make your first Firefox add-on with the Mozilla Add-ons Builder
This new tool, which is obviously aimed at boosting both educational and commercial adoption of Firefox's new add-on architecture, is actually constructed from two technologies that we've discussed before: Jetpack and Bespin. Jetpack is the future of Firefox add-on development and promises simpler, more powerful and 'restartless' extensions. Bespin is Mozilla's new Web-based text editor (which I'm not a huge fan of).
The Add-ons Builder basically tacks on a rather pretty (albeit nascent and not-very-useful) 'file explorer' interface to Bespin. It works, but only just. While the SDK helps you find libraries, there's no auto-complete for library methods. The tutorial suggests you look at the source code of other add-ons for inspiration, but there's no way of searching through them -- just a big, page-after-page directory. The only desirable feature of the Add-ons Builder has to be its rapid prototyping; the ability to test your new code with a single click is very cool. I'd much rather use a desktop SDK though!