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. (GPL)

StepMania is a free dance and rhythm game. It features 3D graphics, keyboard and dance pad support, and an editor for creating your own steps. (GPL)

UltraStar Deluxe is Karaoke Software for PC like Singstar for PS2. It is a Fork of the UltraStar Project with many massive improvements. (GPL)