Slackware

> closer to other commercial Unix versions than Slack. If you want to
> *really* learn to hack startup scripts, compile from source and all that
> cool jazz, I think Slackware is a phenomenal learning tool.

Nevertheless, you can do and learn the same things on basically any Linux
distro (as long as it has a compiler and standard Unix tools) or BSD
flavour.

Jeremy C. Reed
http://bsd.reedmedia.net/