The rhythm game osu! was first released by Dean "peppy" Herbert as a free-to-play game on the PC platform.
The first osu! World Cup was held, marking the start of official competitive international tournaments.
Development officially began on osu!lazer, the modern open-source client to succeed the classic osu! game.
osu!lazer replaced the stable client as the main osu! client, marking a major transition in the game's evolution.