EythorE has ported a basic version of the Fusix operating system to the Sega MegaDrive (or Genesis to Americans)
It runs within the BlastEm emulator, and could potentially be run on real hardware with a Sega Saturn keyboard or a modified PC keyboard for the Mega Drive
The port gives the console a working shell and various UNIX utilities, though the 64K of RAM available will limit its usefulness
The port could be expanded if the Mega Drive’s cartridge port and memory map were better understood; this long forum post attempts to shed some light on the subject for any prospective developers.