The best security you can get in a web browser!
Allow active content to run only from sites you trust, and protect yourself against XSS and Clickjacking attacks.
Automate Firefox. Record and replay repetitious work. If you love the Firefox web browser, but are tired of repetitive tasks like visiting the same sites every days, filling out forms, and remembering passwords, then iMacros for Firefox is the soluti...
Find out which websites you can trust. WOT adds intuitive traffic light-style icons next to search results and URLs to help you make informed decisions about whether to visit a site or not.
Restyle the web with Stylish, a user styles manager. Stylish lets you easily install themes and skins for Google, Facebook, YouTube, Orkut, and many, many other sites. You can even customize Firefox and other programs themselves.
The Web Developer extension adds various web developer tools to the browser.
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.
A customizable mouse gestures extension which enables to execute various commands and user scripts with six types of gestures.
IE Tab - an extension from Taiwan, features: Embedding Internet Explorer in tabs of Mozilla/Firefox...
Expand your email area by blocking and removing ads on the right hand side of the screen when using Gmail, Hotmail, Outlook.com and Yahoo Mail.
Adds ClickOnce support and the ability to report installed .NET versions to the web server.
View HTTP headers of a page and while browsing.
YSlow analyzes web pages and suggests ways to improve their performance based on a set of rules for high performance web pages.
http://yslow.org is the official open source website.
FEBE (Firefox Environment Backup Extension) allows you to quickly and easily backup your Firefox extensions. In fact, it goes beyond just backing up -- It will actually rebuild your extensions individually into installable .xpi files.
Collections are groups of related add-ons that anyone can create and share.Explore Collections