The Firebug Web Page Debugger, Firefox versionmore info
Firediff is a Firebug extension that tracks changes to a pages DOM and CSS.more info
Allows exporting data from the Net panel.more info
View and manage cookies in your browser.more info
Easy access to Dojo features: list dijit registry, and inspect visual widgets, view and breakpoint connections and subscriptions.more info
Log to your Firebug Console from PHP.more info
Test Driver for Firebug itself, useful for extension authors.
Edit your css with FireBug and let cssUpdater update the corresponding property and value in your css source file. Pixel push with ease!more info