Apple Unix Server Penelope: Provides a brief introduction to Apple Unix, and detail the procedure used to install A/UX 3.02 and Apache webserver 1.3.19 on a Quadra 800.
Apple-Flavored Unix: Site containing links and information for various UNIX variants that run on Macintosh hardware.
OpenMac: A site that refers to the multiple efforts at porting different flavors of UNIX to the Macintosh and Power Macintosh platforms, primarily representing the Linux for PowerPC and MacBSD projects.
UNIX for Macintosh: Examples, scripts, commands, and some tutorials.