SapphireDb – Open-Source Alternative to Firebase
If you are looking for an open-source replacement of the Firebase Realtime Database, you might also be interested in Icepeak (https://github.com/channable/icepeak) (full disclosure, I'm one of the authors).Icepeak was written because we were unsatisfied with the reliability and with the (occasionally) high latency of Firebase, both for pushing updates via HTTP (>1s for some requests) and for receiving updates over websockets.This was about 3 years ago though, so I hope that Google improved the quality of the service in the mean time.