You can check out Fink (a MacOSX-based source and package manager) at
http://fink.sourceforge.net
It will help you install and use hundreds of UNIX programs, more and more are added everyday. You can install the 'bash' shell if you like (MacOSX ships with 'tcsh' by defaut). There is a good bash manual
http://www.linuxdoc.org on the 'Guides' section.
You can also check out various GUI UNIX frontends for MacOSX at
http://www.versiontracker.com/macosx
Check out 'OpenMan' wich is a good manual page ('man page') frontend for MacOSX, very useful to learn CLI commands.
Quote:
It is safe to say that MAC OS X is growing very fast, but does not have as many command line utilities (Yet!) as older UNIX systems. After all, MAC OS X is barely a year old!!!
MacOSX is a year old but as you know it is NeXTSTEP based which is fairly old in itself (not mentioning its FreeBSD roots). There are so many commands and utilites that it's easy to get lost...
Just installing 'cpan' opens a vast perl universe.
dani++