MINIX Unix variant
MINIX is a free Unix clone written from scratch and does not contain any AT&T code and for this reason the source code is also available. Due to its small size, microkernal-based design and simple documentation, it is well suited to people who want to run a Unix-like system on their personal computer.
The two versions of MINIX still commonly used and found are:
MINIX 2.0 for Intel platforms
MINIX 1.5 for Intel, Macintosh, Amiga, Atari and SPARC