"The GeeXboX is no more than an awesome standalone media player. Why such a name ? Well, its main purpose is to play DivX movies and, as everybody usually call this kind of projects DivX boxes, we'll just prepended a "GeeX", cause that's for the geeks you all are.
GeeXboX is a full operating system, livecd that can run on any machine and it is based on the excellent MPlayer. No need for a hard drive, you just have to put the GeeXboX bootable CD into the CD-Drive of any Pentium-class computer to boot it. Moreover, GeeXboX is free software, created as open-source software. This means that everyone can modify it and build his own release of the GeeXboX.
You may wonder why you should have to boot another operating system to play your media files, but just think about the Mini-ITX platforms like VIA Epia/Eden or Shuttle barebones. It's now affordable to bring DivX to your home cinema, plugging this kind of computer directly to your TV !"