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.
Allows editing of web page content while in Print Preview mode, prior to printing or saving as HTML or PDF. Compacts the layout and removes unwanted content such as adverts, sidebars and blank pages. Any element can be formatted, hidden or deleted.
Make any pages' search functionality available in the Search Bar (or "search box")...
This 15KB restartless add-on will add a "File" -> "Restart" menu item and a ctrl/cmd + alt + r hotkey to restart FIrefox or Seamonkey.
Help make Firefox better. The Add-on Compatibility Reporter enables you to report if the Firefox add-ons that you're using are working properly.
Search bar optimized for quicker switching of search engines.
An add-on which highlights search terms in the scrollbar(s).
Add a drop marker to the combined back/forward button.
Don't like right-clicking? Use this restartless add-on to toggle your App Tabs with a double-click!
Fill in the rest of words as you type them into the location bar
Collections are groups of related add-ons that anyone can create and share.Explore Collections