RethinkDB is alive
Today I learnt that RethinkDB is alive again. Did you hear about it previously? It's extremely modern JSON database with focus on real time operations.
When it was commercial project they failed this game to MongoDB.
But I would not say that MongoDB is more modern, it definitely feels like old good SQL but without schema.
RethinkDB is something really modern and truly realtime for needs of modern world.
Thanks to CNCF for buying source code form previous owner.