38 Add-ons in this Collection
Firebug by Joe Hewitt, Jan Odvarko, others
Greasemonkey by Anthony Lieuallen, Aaron Boodman, others
DownThemAll! by Nils Maier, Federico Parodi, others
The first and only download manager/accelerator built inside Firefox!
LastPass, an award-winning password manager, saves your passwords and gives you secure access from every computer and mobile device.
The Web Developer extension adds various web developer tools to the browser.
Use the Evernote Web Clipper to save things you see on the web into your Evernote account.
A customizable mouse gestures extension which enables to execute various commands and user scripts with six types of gestures.
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!
Advanced Eyedropper, Color Picker, Gradient Generator and other colorful goodies...
Session Manager saves and restores the state of all or some windows - either when you want it or automatically at startup and after crashes. It can also automatically save the state of open windows individually.
— Open web pages saved with Internet Explorer or other browsers (MHT)
— Save many tabs, video and audio reliably, in a single ZIP file (MAFF)
— Return to the original site you saved a page from, and more!
Finds HTML elements matching chosen CSS selector(s) or XPath expression
DOM Inspector is a tool that can be used to inspect and edit the live DOM of any web document or XUL application. The DOM can be navigated using a two-paned window displaying a variety of different views on the document and all nodes within.