SeaMonkey Extensions compatible with version 2.2 for any regular user. If you are missing any, then it is not compatible. Of course, this is not exhaustive list, so visit frequently for any inclusion.
Open links, pages, and bookmarks in any other browser, using right-click context menus or with one click of the drop-down or standalone toolbar buttons. Modify any menu, browser name or location. Incognito/private browsing mode is also supported.
Remembers last selected (hilited) extension/theme/plugin/userstyle in Add-ons Manager. Turn off/on the add-on selection list box and/or fine tune behavior via its Options.
Paste URL or text to any tabs or a new tab and load it immediately, like 'Paste & Go' feature, but unlike 'Paste & Go', this extension will paste text from clipboard to a tab without focusing on the tab first.
Allows recipients to cancel their newsletter subscriptions in the thunderbird interface.
Multiple Addon Deactivator (M.A.D) is an addon that can (de)activate one, many or each addon at the same time
33 weekly downloads
Uses Google Image Swirl to find and display related images
Provides close all blank/duplicate tabs and Close all tabs to the left/right plus many other options.
Shows an indicator on the status bar in front of the link address when the mouse cursor is over a link to a page you have bookmarked or visited before.
Creates XPI files of extensions you have installed.
Transform strings into Title Case, Proper Case, Start Case, Camel Case, Upper Case, and Lower Case. Highlight your text and only changing what you highlighted.
Add missing search-engine detection to SeaMonkey