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.
YSlow analyzes web pages and suggests ways to improve their performance based on a set of rules for high performance web pages.
http://yslow.org is the official open source website.
StumbleUpon is the easiest way to discover new and interesting photos, videos, web pages and more, recommended by a community of experts. Tell us what you are interested in and we recommend page after page of amazing stuff you’d never expect to see.
This official add-on enables Firefox to provide quick fixes for selected issues.
A productive way to organize, read and share the content of your favorite feeds, blogs and news sites. Feedly offers a seamless transition from Google Reader.
Signatures for Gmail, Google Mail, Yahoo Mail
Keep your favorite Extensions synced with all your computers.
An addon for Firefox which enhances Google, Bing, Yahoo! and Yandex search with all their international flavours by adding previews (thumbnails) and additional functionality.
Operator leverages microformats and other semantic data that are already available on many web pages to provide new ways to interact with web services.
(Formerly Local Install) The primary goal of this extension is to provide the tools needed to install and manage extensions and themes locally and tons of other features.
Note: With Toolkit 6.0 Auto Archiving is fully working in Firefox 2.0 and temp...
Detects Duplicate Bookmarks when bookmarks are added and specify where is the previous URL. You can also search and delete duplicates URL already in your Bookmarks.
Firefox 13 support is available from http://bookmarkdd.mozdev.org in version 1.1.1.
Note from Mozilla: This add-on has been discontinued. Try Google Minimalist instead.
CustomizeGoogle enhances Google by adding information and removing unwanted information.