I've run a bunch of diffrent OS. Such as RedHat, Mandrake, Suse, Win95, Win98, Win2K. I have to say they all do about the same. I don't think the OS has as much to do with uptime as what applications you have installed (and running). Obviously the more you have going on inside your machine, the more likely something is to go wrong. The only benefit I can see with a *nix machine is that you really only need to reboot for hardware changes or power outages. As far as overheating, as long as you have ample cooling fans, or some other cooling system ( a friend built a mini-frig into a case) overheating should not be much of a problem.

DeafLamb