Clone Hero - Clone Hero is a free rhythm game, which can be played with any 5 or 6 button guitar controller...
Stack Overflow - Community-based Q&A part of the Stack Exchange platform.
Osu - Osu is Music, Rhythm, Single and Multiplayer video game developed by Dean Herbert.
The Answer Bank - The Answer Bank is the UK’s leading question-and-answer site.
StepMania - Rhythm game for Windows, Mac, and Linux.
Blurtit - Blurtit is a Q&A website. You can ask a question or answer on any question.