Client Customization Kit for Mozilla Firefox
A lot of people, inclucing myself have, long wanted a way to customize parts of Mozilla Firefox. The old Netscape 6 browser had a Client Customization Kit that was designed for ISPs and others who want to distribute a branded version of Netscape 6. Using the Netscape 6 Client Customization Kit you could easily configure popular customizations such as animated logos, default homepage, bookmarks, and installer settings. You can see screenshots of the Netscape 6 CCK here.
There's a project with the aim of offering the same for Mozilla Firefox and now they have release a document describing a preliminary CCK for Mozilla Firefox.
From Overview of the CCK 0.1 for Firefox:
The goal of the first release of Firefox is to produce an XPI file that when installed customizes parts of Firefox equivalent to the Netscape 7 Client Customization Kit. This document will describe how those customizations are achieved. Note that for demo purposes, we have created a Client Customization Kit that customizes the browser as if it were distributed by A9. This is a preliminary Client Customization Kit - use at your own risk.
The zip file is available here