OPSCON Inc's
"We like to think this suite is a unique piece of design work that fits the needs of a diverse transportation company."
The servers we use run Linux.
It's cheap, has very long run times, can be updated without rebooting most of the time, it's made for networking.
A customer of ours has been running the system for over five years now and the database server has been rebooted three (3) times: 1) replace a failed network card, 2) a 3 day blackout, 3) updated kernel version. Eight months without touching the box is good as far as support goes. It is now rebooted every 4 - 6 months just to clear the memory and give things a "fresh" start.