OS/2 was the bomb to run a multi-node BBS on a single machine. It could multitask DOS applications fantastically and reliably. Worked better for us than a multi-machine Novell-based network and more reliably than using desqview. A 486 with 12 MB ram could comfortably run 3 nodes plus an admin console when needed. We used Renegade and then Wildcat. Fun times.