[hardwaresofton]

Another open source "realtime" database, which supports joins, has a nice admin interface, sharding, and realtime queries:

https://rethinkdb.com

It's what mongo should have been from the beginning -- they won the correctness battlew hile mongo won the marketing war.

I should mention that I've had some colleagues run into problems with scaling it so it's not all roses but a database that scales painlessly in every case is AFAIK a fantasy.