osu! is a rhythm game made by Dean "Peppy" Herbert in 2007. It has gotten good reviews and has been recommended by professional gamers as a way of improving cursor aim and gaining advantage in other games. A repository of the game, mostly written in C#, can be found in GitHub.
- Carpenter, Nicole (2019-07-16). "Gamers with godlike reflexes are racing to break world records in this rhythm game". PC Gamer. Retrieved 2021-04-26.
- Webb, Kevin. "Professional gamers like Ninja use this music game to practice their aim and improve their mouse skills — here's how you can play for free". Business Insider. Retrieved 2021-04-26.
- ppy/osu, ppy, 2021-04-26, retrieved 2021-04-26