GuitarsOnFire is a GuitarHero clone, like Guitarfun and FretsOnFire. It uses FretsOnFire compatible songs, which can be found all over the internet. Everything is released under GPL.

Changes:

Customizable scriptable stages. 3 stages included by default (GuitarsOnFire, Guitarfun, Mario)
Lefty flip
Load all GFX from png files on SD card
Load drums.ogg if it exists
‘lower fret overriding’
Sound fix when no song.ogg is found
Gamecube controller support (Untested)
Classic controller support (Untested)
Not showing a difficulty if there are less then 10 notes (some songs just add a single note to show up as having all difficulties)
Added ‘start’ key for keyboard
No songs message when no songs are found
Fix scoring for sustained notes
Remove tails for short notes
Add neck/highway gfx
Failing a song when playing badly
Keyboard keymap customizing
Basic drum track support

http://wiibrew.org/wiki/GuitarsOnFire