Centrifugo
Apache-2.0 Go realtime server binary, not in-process Socket.IO
Comms / Realtime · Apache-2.0 · 10.7k
What's Good
Apache-2.0. Language-agnostic PUB/SUB: WebSocket, HTTP-streaming, SSE, gRPC, WebTransport. Official SDKs. docker run centrifugo. Decouples transport from business logic.
The Catch
You run it. This is not Socket.IO in-process. Cloud/PRO SKUs were unverified here — no invented Cloud prices. Ops, clustering, and Redis when you scale stay yours.
Verdict
Apache-2.0 realtime binary. Free as in you operate the server.
Embed
[](https://stackgems.com/gems/centrifugo)