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

Features:

* Attractive libwiigui-based interface, designed with the Wii in mind
* Picture viewer
* Music player
* On-line media support, including SHOUTcast, YouTube, and Navi-X
* FAT32/NTFS from SD and USB 2.0 (FAT32 recommended)
* Network playback via SMB, HTTP, and FTP
* Multi-language support: Chinese (Simplified and Traditional), Dutch, English, Estonian, French, German, Hungarian, Italian, Japanese, Korean, Polish, Portuguese (Brazilian), Romanian, Russian, Spanish

Changes:

Synced to MPlayer r32709
Fixed image stuttering and audio sync issues
Fixed pointer alignment on DVD menus
Added ISO/IFO DVD playback, with DVD menu support
Added screen resizing while watching a video via the Wiimote. Just hold down B and use the arrow keys (thanks clava!)
Performance optimizations using paired singles (thanks Extrems!)
Improved USB compatibility
Added support for playlist files in the Videos and Music areas
Enable negative subtitle delay values
Replace libmp3 with libmpg123. Fixes a number of MP3 audio bugs
Added a setting to change the starting area
New JPG scaler for the Picture Viewer (thanks puddles!)
Display artist and song on separate lines for SHOUTcast (thanks jhb50!)
Added settings for YouTube quality and caching for online media
Subtitle autoscaling
Added a delay on startup so those with slow USB drives are not bumped back to the main browser list
Shifted all GUI elements inwards to fix left/right cropping occuring on 16:9 for some people
Fixed a Picture Viewer crash
Fixed lowercase bug for NTFS
Many other minor fixes and improvements

http://www.wiibrew.org/wiki/WiiMC