Blocks annoying video ads on YouTube, Facebook ads, banners and much more.
Adblock Plus blocks all annoying ads, and supports websites by not blocking unobtrusive ads by default (configurable).
The first and only download manager/accelerator built inside Firefox!
The User Agent Switcher extension adds a menu and a toolbar button to switch the user agent of a browser.
A customizable mouse gestures extension which enables to execute various commands and user scripts with six types of gestures.
View HTTP headers of a page and while browsing.
Adds toolbar buttons to the customize toolbar window in several programs including Firefox, Thunderbird and SeaMonkey. Some of the buttons make commonly preformed actions quicker, others add new functionality.
Make any pages' search functionality available in the Search Bar (or "search box")...
Make your browsing experience faster by avoiding wait time on DNS lookups
The greatest user script engine on the Internet (a fork of Greasemonkey).
FoxyProxy Basic is a simple on/off proxy switcher. More advanced features and configuration options are offered by FoxyProxy Standard.
Monitors web pages for updates. Useful for websites that don't provide Atom or RSS feeds.
Help us make Firefox better by joining our structured user studies! No need to download this add-on if you are running Firefox 4 beta, - you are already a part of the team!
Supports to hide Menu Bar automatically, you can press the ALT key to show it temporarily.