10. Various PC Oses

Here's a list of various operating systems that have been known to run on PCs. Some are thinly-veiled renamings of other OSes (for instance, DR-DOS was purchased by Novell, thus becoming Novell DOS, which later became Caldera OpenDOS).

• CP/M-86 / MP/M-86 / Concurrent CP/M-86 / Personal CP/M-86

• IBM PC-DOS

• MS-DOS

• DR-DOS, which became Novell-DOS, which became Caldera OpenDOS

• PTS-DOS

• SDOS

• DOS/V

• Windows 95

• Windows NT 3x

• Windows NT 4x

• Coherent Unix

• FreeBSD

• Interactive Unix

• Linux

• L3

• L4

• Mach

• VSTa

• Lynx OS

• Hurd

• Plan 9

• Inferno

• BeOS

• SPIN

• Minix

• NetBSD

• NeXT Step

• OpenStep

• SCO Unix

• Solaris

• UnixWare

• Xenix

• CTOS

• NetWare

• OS/2

• Pick

• QNX

• THEOS

• Flux OS

• AtheOS

  A GPLed OS for IA-32 systems that supports much of the "POSIX" stuff that allows it to generally run Unix-like software.

  It provides a non-X client/server GUI that uses threading and is generally programmed using C++.

• Syllable - was AtheOS