I don't think many people are aware of it, but Gentoo Prefix is a valid alternative to MacPorts and Fink for installing unix-y type software on Mac OS X.
Personally, I just use it to install all those command line tools and utilities I miss from Linux.
Here's my development-centric laundry list of things I've used it to install:
- version control
- cvs
- darcs
- git
- Java stuff (yep, it supports Java using Apple's SDK)
- ant
- maven
- Others
- nmap
- keychain
So remember kiddies, Gentoo works on Mac OS X too!