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).
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.
Fight the text ads! Element Hiding Helper is a companion extension for Adblock Plus meant to make creating element hiding rules easier.
FoxyProxy is an advanced proxy management tool that completely replaces Firefox's limited proxying capabilities. For a simpler tool and less advanced configuration options, please use FoxyProxy Basic.
A customizable mouse gestures extension which enables to execute various commands and user scripts with six types of gestures.
Control what gets sent as the HTTP Referer on a per-site basis.
Open Bookmarks/History/Homepage/URL/Search in new tabs, and more utilities for tabbed browsing, including Protect/Lock/Faviconize/Unload Tab, Reload Every, Select and manipulate multiple tabs simultaneously, Tab Stacking/Coloring, etc.
DOM Inspector is a tool that can be used to inspect and edit the live DOM of any web document or XUL application. The DOM can be navigated using a two-paned window displaying a variety of different views on the document and all nodes within.
Screengrab! saves webpages as images... but not for new versions of Firefox.
FF changes too fast and I don't have the time to maintain it anymore. Bugs have developed that I am not in a position to investigate.
Therefore, Screengrab is EOL.
This extension can simplify the rule to just specify the URI and Content type and can enable/disable each rule separately.
What's more, it can customize the web pages by user scripts which is similar to Grease Monkey.
Open Bookmarks/History/Homepage/URL/Search in new tabs, and more utilities for tabbed browsing. This is a lite version of Tab Utilities (http://addons.mozilla.org/addon/59961).
Transforms typed or static text to L337, ROT13, BASE64, HEX, URL, BIN, DES, AES, Morse code, DVORAK keyboard layout and to lower/to upper case functionality, Leet Font...
Note from Mozilla: This add-on has been discontinued. Try DragIt instead.
Allows you to open links in new tabs, and do more with drag and drop gestures easier.
Collections are groups of related add-ons that anyone can create and share.Explore Collections