Security updates for SeaMonkey 2.x regularly occur, keep up to date with them on the Project News page.
SeaMonkey 2.3 and beyond
Stable releases will be more frequent (6-week release schedule) but with fewer changes, eliminating the need for minor releases. The aim is to release the stable versions right around a week of the release of the equivalent Firefox and Thunderbird.
SeaMonkey 2.2 was released on July 8th, 2011.
With SeaMonkey 2.2, the SeaMonkey project has joined the Rapid Release train.
SeaMonkey 2.1 was released on June 10th, 2011.
SeaMonkey 2.1 was built on top of the platform shared with Firefox 4.0 and Thunderbird 3.3. It completed the transition to the Places back-end (which is now used for bookmarks, too), allowing to integrate Sync (formerly an add-on) directly into the suite, and adapted the back-end for out-of-process plugins, Omnijar and libxul. This release is based on the Mozilla 2.0 platform.
SeaMonkey 2.0 was released on October 27th, 2009.
SeaMonkey 2.0 was completely revamped to build on the newer software toolkit used by Firefox 3.5 and Thunderbird 3.0, which meant a lot of changes and a need to migrate profile data from the old to the new structure but warped the suite forward to a much more modern and powerful add-on system and a well-maintained platform. This release is based on the Mozilla 1.9.1 platform.
SeaMonkey 1.1 was released on January 18th, 2007.
SeaMonkey 1.1 builds on SeaMonkey 1.0 and improves it with a few additional features as well as picking up development and bug fixes from the Gecko 1.8 branch. The basic structure of source, backends and the application remains unchanged and continues the "tradition" we picked up from Mozilla suite. This release is based on the Mozilla 1.8.1 branch. It does not longer receive security updates.
SeaMonkey 1.0 was released on January 30th, 2006.
This first release (SeaMonkey 1.0) continued development from the 1.8 beta1 release by the Mozilla Foundation - the final product is fundamentally the same (just with the new name, picking up core development that has been done since, and integrating some further work done by our developers). This product is based on the Mozilla 1.8.0 branch. It does not longer receive security updates.