linux browsers and website compatibility

I truthfully think thats a bit overkill because there are so many browsers out there. When I design I only stick with the big 3, IE Safari, Firefox. I can't speak for Ubuntu specifically, but as long as the libraries for the base of KDE and XFCE are in the repository, you should be able to install them all fine. Or you can use: http://browsershots.org/ I've used it a few times, its a pretty neat service. :) If you need to install multiple IE clients on the same machine try: http://tredosoft.com/Multiple_IE I've use that as well, works fine.