The BSD family used to be the reference for Unix-like OSes. Since then, the standard has become POSIX, and 4.4BSD has split into lots of diverging projects:

They all seem to have some binary compatibility with Linux, at least on the i386 platform.

Pages in this topic: DragonFlyBSD   FreeBSD   Lites   NetBSD   OpenBSD   TrustedBSD  

Also linked from: DOS   KallistiOS   Mac OS X   Mach   MachTen   Microkernel   Microkernel Debate   OS161