As of July 2012, Thunderbird has transitioned to a new governance model, with new features being developed by the broader free software and open source community, and security fixes and improvements handled by Mozilla.
Thunderbird is a free, open-source, cross-platform e-mail and news client developed by the Mozilla Foundation. The project strategy is modeled after Mozilla Firefox, a project aimed at creating a Web browser.
- The previous issues with Japanese Mac builds have now been fixed, and Thunderbird will no longer need to be run in 32-bit mode.
- Installing extensions within Thunderbird no longer requires download and installing as a file
- Security fixes
- OS X 10.6 or later