Listening for DOM load for FireFox extensions so you can modify the DOM before any elements (e.g., JavaScript, images, etc.) have loaded.

This tutorial explains how to create a toolbar extension for the Firefox web browser (specifically for version 1.5 and later). It provides an overview of how extensions are developed, the tools required to create an extension, and details on how toolbars are created.

This tutorial will take you through the steps required to build a very basic extension - one which adds a status bar panel to the Firefox browser containing the text "Hello, World!"