I want to compile a portable version of Firefox 3 on a low cost Intel Celeron Windows Xp machine to run as a kiosk computer. So i just want the browsing functionality since i'll be running it on the fullscreen mode. What are the steps to do a minimal rebuild from the sources? Also what is firefox's command line parameters to open a site from the cmd?
There is a Kiosk mode addon (more for a lock-down) for Firefox.
You may be in general interested in this other question here:
How to lock down Windows XP for use as an internet kiosk?
Here is a gHacks reference for custom builds.
and, a Prism reference.
A "Stripped down minimal build" doesn't really make any sense. You can't really exclude any functionality that would make it run faster or be any smaller, since most of the code that Firefox needs to render webpages is the same code that it uses to render its user interface. Forget about trying to "strip down" the code.
That being said, it sounds like you probably want to use XULRunner, which will let you use all the web browsing functionality of Firefox, but wrap it in your own GUI. You can find an ultra-minimalist browser XUL application here:
http://benjamin.smedbergs.us/xulrunner/mybrowser-0.2.2.xulapp
http://webconverger.com/ provides a minimalistic OS build featuring Firefox. There is also build instructions if you want to build your own customised images.