I’ve been using the Ruby based testing framework called Watir for testing web pages. I wrote a test suite on my Mac to test with the Mac browser and with only a few header changes was able to use the same script on Windows to test with IE. Now if they can just make a Linux version of the libraries that can test Firefox, I will have all bases covered. Actually, I think someone is working on that already at least on Windows and it’s called FireWatir.
Be nice to get it for Linux.