Firebug The Firebug Working Group 1.7.3

The Firebug Web Page Debugger, Firefox version more info

Eventbug Jan 'Honza' Odvarko and John J. Barton 0.1b9

This extension brings a new Events panel that lists all of the event handlers on the page grouped by event type. The panel also nicely integrates with other Firebug panels and allows to quickly find out, which HTML element is associated with specific event listener or see the Javascript source code. more info

Firediff Kevin Decker 1.1.3

Firediff is a Firebug extension that tracks changes to a pages DOM and CSS. more info

SelectBug 0.1a3

List elements for each CSS selector, trial CSS selectors by typing them in.

NetExport Jan 'Honza' Odvarko 0.8b17

Allows exporting data from the Net panel. more info

FireCookie Jan 'Honza' Odvarko 1.2.1

View and manage cookies in your browser more info

Illuminations for Developers Steven Roussey 1.1.10

Enhances Firebug to understand JavaScript libraries and frameworks (like ExtJS, Dojo Toolkit, SproutCore, Closure Library, qooxdoo, YUI3, and jQuery/jQueryUI), making things more obvious and helpful when debugging. Trial version. more info

Dojo Firebug Extension Patricio Reyna Almandos and Fernando Gomez 1.0a9

Easy access to Dojo features: list dijit registry, and inspect visual widgets, view and breakpoint connections and subscriptions. more info

FirePHP 0.5.0

Log to your Firebug Console from PHP more info

FireStarter 0.1.a6

Extends Firebug's activation model with advanced features.

FBTest 1.7b17

Test Driver for Firebug itself, useful for extension authors

Tested with Firebug