The SeaMonkey project provides official versions of SeaMonkey 2.22.1 for Windows, Linux, and Mac OS X in US English and experimental language packs for a small variety of other languages. Community volunteers are also contributing builds for other platforms. You can download SeaMonkey 2.22.1 here

Before installing, make sure your computer meets the system requirements . SeaMonkey 2.22.1 will no longer offer to migrate your data from SeaMonkey 1.x or Mozilla 1.x at the first start after installation ( bug 689437 ). In order to upgrade from such an old version, install the last SeaMonkey 2.0 release first, do the one-time profile upgrade, uninstall SeaMonkey 2.0 and then install your target release (e.g. this one).You can find more details about installation, profile data and uninstallation in our install and uninstall document.

Extensions installed under SeaMonkey 1.x are not migrated to SeaMonkey 2, and may not be compatible for reinstalling in this version due to major changes in our architecture. Please report any issues to the maintainer of the extension. Extensions and Themes for SeaMonkey 2.22.1 can be installed from the SeaMonkey Add-Ons website or the "Get Add-Ons" section in the Add-ons Manager.

If you want to check whether your most important add-ons are already compatible with the SeaMonkey version to be installed, please refer to the SeaMonkey Add-ons Compatibility Tracking wiki page for an overview.

Extensions with binary components such as Lightning, Enigmail and HTML Validator only work on certain platforms (e.g. Windows). Furthermore they need to be adjusted for each new SeaMonkey release, which also means that an old version of such an add-on can break SeaMonkey if you disabled compatibility checking (which e.g. happens when you install the Add-on Compatibility Reporter add-on).

Lightning provides versions compatible with the latest SeaMonkey beta through its Development Channel which has an own section at the bottom of the Lightning add-on page. Other Lightning releases can be found on the Calendar Versions page.

For Enigmail, please refer to the Enigmail Nightly Builds page.

For HTML Validator you need to check whether the Firefox version that appears on SeaMonkey's about: page is listed on the 0.9x download page. Note that only Windows is supported at this time.