osu! has multiple release streams, or game client versions, that receive updates at different rates. In order to catch potential issues early, new features and changes are added into preview versions before making their way to the main client.
| Release stream | Client | Notes |
|---|---|---|
Stable |
osu!(stable) | Most recent full release of osu!(stable); feature-locked; receives updates after Cutting Edge (Experimental). |
Cutting Edge (Experimental) |
osu!(stable) | Receives osu!(stable) updates earlier; feature-locked; contains a few extra features compared to Stable; multiplayer only available to osu!supporters. |
Lazer |
osu!(lazer) | Completely rewritten game client; open source; most active in development with many differences and new features. |
Tachyon (Unstable) |
osu!(lazer) | Pre-release version of Lazer; receives osu!(lazer) updates earlier and more frequently. |