Instantbird 0.3 alpha 1 has just been released.
This release contains very significant changes, including the ability to create JavaScript protocol plugins and the upgrade to the Mozilla 2.0 platform. Most of the changes are not yet visible in the user interface, so we would not advise current users of the 0.2 version to update.
However, it includes basic support for Twitter and is already quite stable; so it will please early adopters and testers who don’t go as far as to use nightly builds (which update themselves everyday with the newest code). Add-on developers will also be interested, especially because of the new ability to create restartless add-ons.