XBMC: maybe the best media center
XBMC is a cross-platform software available for #Linux, Mac OS X, Microsoft Windows operating-system, as well as the original Xbox game-console. I am using it since 2003 on my XBOX
XBMC is currently available for #Ubuntu #Linux, Mac OS X (Intel-based Leopard and Tiger), Microsoft Windows, and the original (first-generation) Xbox. We are currently at Beta 1 for our upcoming release code named Atlantis. It should be noted that XBMC requires OpenGL 1.4 support, at a minimum, to function. We do however recommend OpenGL 2.0 to fully experience XBMC. Check your graphics drivers to see what version of OpenGL your GPU (graphics processing unit) supports.