SeaMonkey 2.21 發布， 互聯網應用套件

它是一個互聯網應用套件，包括：一個網頁瀏覽器、一個高級郵件程序、一個IRC聊天客戶端和一個HTML編輯器。

SeaMonkey曾經是Mozilla基金會內部一個負責管理工作的小組的名稱。SeaMonkey致力于在從過去的“Mozilla瀏覽器套件”中分離出來的代碼的基礎上，開發可供使用的瀏覽器套件。它成功的繼承了Netscape Communicator的衣缽。

該版本基于Firefox4，應用了最新網絡技術如HTML5，硬件加速技術并改善了JavaScript的速度。

發布說明: Implements an option to thread messages received by date. Allows deletion of news posts by default. Implements optional taskbar preview-per-tab. Adds support (permission prompt) for desktop notifications. Adds an Isn't operator for searching by priority. Support for a new scrollbar style on Mac OS X 10.7 and newer. Accessibility-related improvements on using pinned tabs. Major SVG rendering improvements around Image tiling and scaling. Removes support for sherlock files that are loaded from application or profile directory. Support for W3C touch events is disabled