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.
Never be annoyed by a Flash animation again! Blocks Flash so it won't get in your way, but if you want to see it, just click on...
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.
NoSquint allows you to adjust the text-only and full-page (both text and images) zoom levels as well as color settings both globally (for all sites) and per site.
Status bar widgets and progress indicators for Firefox 4+
A very compact & highly customizable theme that minimizes space consumed by menu & tool bars without hurting the overall usability. Supports Windows, Mac & Linux.
British English Dictionary R1.19 for Firefox, Thunderbird and SeaMonkey by David Bartlett.
To enable, right-click in a multi-line text box, select "Languages", then "English / United Kingdom".
Useful tools for the nightly tester.
This add-on allows one to customize the theme "Classic Compact". Options include: 10 different toolbar button sets; turning off gradient backgrounds; OS scrollbars; dark system color support; merging menu bar into one menu button; etc.
Quick popup allowing you to view a calendar or pick a date. ...
Collections are groups of related add-ons that anyone can create and share.Explore Collections