Le portail maintenant est : https://addons.mozilla.org/en-US/developers/ orienté vers JetPack, voir aussi l’outil inter-actif.

MDC : Building an Extension
MDC : Setting up an extension development environment

Chromebug User Guide

JavaScript Debugger
JavaScript debugging in Firefox extensions
Enabling the javascript.options.showInConsole and javascript.options.strict options are a good help. Also enabling nglayout.debug.disable_xul_cache and browser.dom.window.dump.enabled doesn’t hurt anything, though I don’t consider these options as useful.
Firefox extension debugging
Firebug a really handy logging interface that you can dump debugging info to.
Firebug.Console.log()

EDE : Pas dans firefox 3, car pas de mise à jour sécurisée How to use Extension Developer’s Extension in Firefox 3
Extension Developer’s Extension Testing JavaScript code, prototyping XUL layouts, and building XPI packages are all made easier by this extension.

• Extension Builder Build your extension’s package (jar and xpi files)
• install.rdf Editor
• Javascript Shell : set your scope to any open window or webpage (using enumerateWindows) to run javascript as if it were in that document
• Javascript Environment : run blocks of javascript code.
• Live XUL Editor
• Live HTML Editor
• JRX: real-time JavaScript RegExp evaluator
• Interactive XPath Tester
• Enable Debugging Prefs
• Reload All Chrome : testing overlay changes without restarting.