Welcome to osu!, a free-to-win rhythm game developed by peppy with four game modes: osu!standard, a circle clicking simulator; osu!taiko, a drumming emulator; osu!catch, a fruit salad catcher; and osu!mania, a key smashing synthesizer.
Main page: Beatmapping.
Beatmapping is the process of a creator creating a beatmap. This process includes: selecting music, timing and mapping the beatmap, and testing the beatmap. It might also include: adding a video, adding a storyboard, and/or adding a custom skin. All of those can be done by the creator alone or with other users, sometimes referred to as storyboarders, skinners, and/or guest creators, depending on what they do.
Main page: Modding.
Modding is the process of users reviewing (or commonly called "modders") a creator's beatmap in the pending (or work in progress/help) stage. Modding plays a big role in quality control because this allows creators to fix issues with their beatmap.
Main page: Skinning.
See also: Skinning Tutorial.
Skinning allows anyone to change the way osu! looks and feels. This can be as small as changing the cursor or as big as redoing the appearances of all the game modes and interface.
Since 2016-08-26, the osu! wiki has moved to a GitHub repository. After this change, the workflow has drastically changed. All contributions now go through the osu-wiki GitHub repository and are reviewed before being approved and merged to the osu! wiki.
To get started, see the osu! wiki Contribution Guide.