Last Friday, it was announced that Firefox 3.1 will be renamed to Firefox 3.5. What does this mean for add-on compatibility?
Right now, Firefox 3.1b4pre is available as a maxVersion on AMO, and can be used by any add-ons that support current Shiretoko builds. On Tuesday, March 17, these builds will be renamed to 3.5b4pre, and the maxVersion on AMO will be renamed accordingly. This means that as an add-on developer, if you mark your add-on as compatible with 3.1b4pre before Tuesday, it will automatically change to support 3.5b4pre when necessary. After Tuesday, developers can simply start using 3.5b4pre as their maxVersion.
Similarly, Firefox 3.2a1pre will be renamed to 3.6a1pre on Tuesday. Any add-ons currently compatible with 3.2a1pre will automatically be 3.6a1pre compatible on Tuesday.
Followers of the add-on compatibility dashboard may notice that it will no longer be accurate after the renames on Tuesday. The AMO team is planning to support version grouping of Firefox 3.1 and 3.5 with its 5.0.4 release to be deployed on April 9.
Additional compatibility updates will be posted here on the Mozilla Add-ons Blog.