XBMC is an award-winning free and open source (GPL) software media player and entertainment hub for digital media. XBMC is available for Linux, OSX, Windows, and the original Xbox. Created in 2003 by a group of like minded programmers, XBMC is a non-profit project run and developed by volunteers located around the world. More than 50 software developers have contributed to XBMC, and 100-plus translators have worked to expand its reach, making it available in more than 30 languages.
While official development has stopped for the Xbox version, un-official updates are still being made and released on a very frequent basis.
XBMC can read pretty much any audio, video, and picture format, making it easy to find and view/listen to your favorite images/videos/music.
XBMC for both PC operating systems and the Xbox have the ability to use Plugins, Scripts, Programs, and Add-ons developed and scripted by either XBMC users or developers. Like to browse YouTube? Do it from your Xbox with a Plugin! Like to listen to Grooveshark? Download the Grooveshark script!
I can confirm that this is totally kickass on the Xbox, while I have only used a third-party developed program based on the XBMC engine called "Boxee" for the PC, which was still pretty good.
