I just installed Ubuntu linux on my soon to be CNC machine's computer. (Have I said too much?)
It's fantastically good. It's running a tri-boot with Windows XP and Vista.
With Windows, I had to configure all my drivers, go through a long set up, set up my network, etc.
Ubuntu's set up took less than 10 minutes from me putting in the disk to me writing this. It automatically got together all the drivers and detected network settings all by itself. I'm listening to music, browsing the forums, chatting on Gaim, and browsing Myspaces. For free. And with this distro of linux, you can have 4 workspaces. 4 workspaces! It's an awesome feature!
I recomend every one check out Ubuntu or at least some form of Linux. It's awesome. And, you can run it completely as a live CD if you so wish, so you can try it out before you commit to installing it on an HD.