> 3.x, 4.x ran on relatively regular 32-bit PC server hardware. 2.x ran on the 80286 in protected mode, the only OS I know which did that.

My friends father worked for a shipping company and their office ran off a 286 Netware server until the early 2000's. It was a big white label tower with classic orange monochrome monitor and large Epson dot matrix printer with tractor feed paper.