I hammer all these systems (automated/parallelized and run for most of the day) with production software for living. We run both memory intensive and CPU intensive jobs. My experience somehow is, if the program goofed, Linux and Unix systems kick out the program or stop execution without giving in to much sabotage. Macs to a little bit lesser extent. Windows is most likely to succumb to such and freeze. As a result Linux and Unix systems run for months without needing a reboot. Macs again to a little bit lesser extent. We had to schedule daily auto reboots on Windows machines to get things going smoothly on those.
Some people say Linux/Unix/OSX(Unix backend) machines are stable because not many programs run on them, but some say that's mostly because they are hard to crack due to their solid design.
This is just my experience. I don't meant to argue with or contradict anybody.
Shiral
[This message has been edited by shiral (edited 02-24-2006).]