WiiMC (Wii Media Centre) is an open source media player for the Nintendo Wii. The GUI is powered by libwiigui.

Features:

– Synced to MPlayer 32866
– Fixed crash for some USB drives
– Added option to change screensaver delay
– Fixed incorrect warning about picture sizes being > 6MB
– Improved network initialization routines
– Improved subtitle scaling calculations
– Improved shutdown – if WiiMC fails to shut down within 5 seconds, shutdown will be forced
– Experimental USB DVD drive support (thanks clava!)
– Other minor optimizations and improvements

http://wiibrew.org/wiki/WiiMC