If you are an add-on fan and missed the Mozilla Add-ons blog post about the new Add-on Collector release (1.1), be sure and go and read it:
Add-on Collector now supports Thunderbird, Seamonkey, and Mobile
This is a project that Dave and I at Briks really enjoy working on. The challenge for this release was making it work with Thunderbird (TB) 2, and mobile support. Thunderbird 2 uses the Mozilla 1.8 branch which meant that the Add-on window overlay code was different. We threw away the overlay bindings and built them from scratch. It’s rarely fun supporting old platforms, but when we started the port TB3 was not out yet. TB3, and Seamonkey (SM), in comparison was a breeze as the toolkit code is the same as Firefox 3.x. Thanks to Igor Velkov for the SM patch.