Does Realtime/Push Pub/Sub DB open source analogue of Firebase exist?

Question

Database

I know there is RethinkDB, but it's sad that development is dying despite the Linux Foundation (there is a scandal that former team members hold the keys and do not update the release, which has been ready for half a year already).
There is also deepstream.io, but this is a little different, I want a complex solution with a database.
Parse is also clear.
What else is there in this niche?