52 Add-ons in this Collection
The easy way to download and convert Web videos from hundreds of YouTube-like sites.
Greasemonkey by Anthony Lieuallen, Aaron Boodman, others
DownThemAll! by Nils Maier, Federico Parodi, others
The first and only download manager/accelerator built inside Firefox!
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.
Displays a country flag depicting the location of the current website's server and provides a multitude of tools such as site safety checks, whois, translation, similar sites, validation, URL shortening, and more...
Use the Evernote Web Clipper to save things you see on the web into your Evernote account.
Xmarks is the #1 bookmarking and open tab add-on. Keep your bookmarks, and open tabs backed up and synchronized across computers and browsers. Mobile phones with Premium access. Utilize LastPass to sync passwords!
United States English Spellchecker for Firefox, Thunderbird and SeaMonkey by Kevin Atkinson and Geoff Kuenning.
To enable, right-click in a multi-line text box, select "Languages", then "English (United States)".
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)
IE Tab - an extension from Taiwan, features: Embedding Internet Explorer in tabs of Mozilla/Firefox...
Advanced Eyedropper, Color Picker, Gradient Generator and other colorful goodies...
Use PDF Download to do whatever you like with PDF files on the Web. Regain control and eliminate browser problems, view PDFs directly in Firefox as HTML, and use the all-new Web-to-PDF toolbar to save and share Web pages as high-quality PDF files.
Draw a ruler across any webpage to check the width, height, or alignment of page elements in pixels.
Visual bookmarks for Firefox. (Works with all latest versions of Firefox)