From the site:
“Frets on Fire is a game of musical skill and fast fingers. The aim of the game is to play guitar with the keyboard as accurately as possible.”
It uses 3D accelerated OpenGL, and is available for Windows and Linux. It contains 3 songs.
i read about it from the assembly.org site web site, and at Slashdot.
official site:
http://louhi.kempele.fi/~skyostil/uv/fretsonfire/