13 Best Mozilla Firefox Extensions *No idea they existed*

Firefox Add-on Enables Web Development Across Browsers and Devices

Coding Firefox directly in the Web (using Cloud9 and Janitor)

Capture Any Color on the Web with the Firefox Eyedropper

A Better Firefox Add-ons Manager

Opening the Add-on Debugger

Build a Firefox Extension from Scratch

How to build(compile) Mozilla Firefox on your development computer from the source code