NATS
Apache-2.0 subject-based messaging and streaming fabric
Comms / Realtime · Apache-2.0 · 20.7k
What's Good
Apache-2.0. OSS self-host at $0. Pub/sub, request/reply, queue groups, JetStream streaming. Tiny Go server, clients across languages. CNCF project.
The Catch
Subject-based messaging/streaming fabric — not an in-process WS lib and not a Go realtime binary alone. Distinct from Socket.IO and Centrifugo.
Verdict
Apache-2.0 messaging fabric. Free as in you run the server. Not Socket.IO.
Embed
[](https://stackgems.com/gems/nats)