Tab Mix Plus enhances Firefox's tab browsing capabilities. It includes such features as duplicating tabs, controlling tab focus, tab clicking options, undo closed tabs and windows, plus much more. It also includes a full-featured session manager.
The Web Developer extension adds various web developer tools to the browser.
Theme Font & Size Changer lets you change the global font size and font family used for the user interface in Firefox. Design your browser with your favorite font.
Facebook Toolbar Button lets you visit your Favorite Facebook quickly and easily by adding a special Facebook Button to your Toolbar.
Play for free: Action games, Adventure games, Arcade games, Board games, Card games, Educational games, Puzzle games, Role Playing games, Sports games, Strategy games, Virtual games, Logical games, Addictive games, Extreme and Funny games.
Customize Your Web (CYW) let's you customize your favorite websites with just a few clicks. What Greasemonkey is for developers is CYW for non-developers. You can remove/rearrange /modify elements, add keyboard shortcuts and do many other things.
Web Mirror Viewer displays various internet mirrors of an open tab or right-clicked link via the right-click context menu. Useful for dealing with dead pages/broken links and getting around proxies.
Adds a button to easily convert any YouTube video into a High Quality mp3 directly on YouTube.