Operating System discussions often degenerate into HolyWars
. Let's not do that here.
Check one or more platforms:
OsWin: Windows 95 / 98 / NT / 2000 / ME /CE
OsNewton Apple's Newton, the large print edition of the PalmPilot
OsPalm: Palm Pilot
OsPlan9 PlanNine from BellLabs runs on most platforms, e.g. x86, sparc, mips, arm, 68xx, alpha, ppc, i960, ...
OsInferno The Inferno OS is designed to run in machines with very little ram
See also TWikiCategory