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).
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.
The Web Developer extension adds various web developer tools to the browser.
Reloads web pages every so many seconds or minutes. The function is accessible via the context menu (menu you get when you right click on a web page) or via tab context menu (right click on the tab)
Use tamperdata to view and modify HTTP/HTTPS headers and post parameters...
German Dictionary (new Orthography) for spellchecking in Mozilla products
A clean, easy to use and highly extensible Internet Relay Chat (IRC) client.
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.
German dictionary igerman98 (de_DE, Germany), for Firefox, Thunderbird und Seamonkey.
Bypass compulsory web registration with the context menu via www.bugmenot.com.
Useful tools for the nightly tester.
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".
Collections are groups of related add-ons that anyone can create and share.Explore Collections