This may be more suited to Tilted Computers. All the same.
I checked with one of my Mac guys, because I wanted to be sure of this before I posted it, but the new Mac OS versions (OSX) are all based off of a hybrid of BSD and Gentoo. I knew that without double-checking; what I wasn't sure of was the capabilities of OSX. Basically any media player and/or download software for Linux ought to work fine under OSX, although it may require a little more setup than the Mac native stuff. If you're looking for downloads and don't care about the legality of it, there are about eight thousand different bittorrent clients to be had out there; if it's playback that you need, you can grab something like XMMS. He suggested
sourceforge.net as a good place to start.