The first and only download manager/accelerator built inside Firefox!
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.
With gtranslate you can translate any text in a web page just by selecting and right-clicking over it. The extension uses the Google translation services to translate the text.
FEBE (Firefox Environment Backup Extension) allows you to quickly and easily backup your Firefox extensions. In fact, it goes beyond just backing up -- It will actually rebuild your extensions individually into installable .xpi files.
Visual bookmarks for Firefox. (Works with all latest versions of Firefox)
The extension previously known as GooglePreview. Inserts preview images (thumbnails) and popularity ranks of web sites into the Google, Yahoo, Bing and DuckDuckGo search results pages.
AddThis for Firefox is the best add-on to make sharing and bookmarking simple. Have all your favorite web 2.0 social networking, bookmarking, blogging, and e-mail services at your fingertips. Share any page, anytime, with anyone.
New Tab King is the premier extension for turning your new tab page into a beacon of productivity and efficiency.
Featuring a todo list, recently closed tabs, most visited pages and more!
Tons of visual customization option too!
Open IT Online allows you to open documents and images online without the need of any software to be installed. It supports Google Docs, Zoho, View Docs Online, Vuzit to edit/view documents and Snipshot, Pixlr, Sumo Paint, etc. to edit/view images.