We were also looking for an open source Firebase a while ago, packed with some extra features like multiple db support and push notifications. Ended up building

We were also looking for an open source Firebase a while ago, packed with some extra features like multiple db support and push notifications. Ended up building http://telepat.io http://telepat.io. Docs & specifications at http://docs.telepat.io/ http://docs.telepat.io/. Hope this helps you.