RethinkDB

RethinkDB is the first open-source, scalable, NoSQL database for building realtime applications. It pushes JSON to your apps in realtime and makes building realtime apps so much easier.

RethinkDB exposes a new database access model where the developer can tell the database to continuously push updated query results to apps without polling for changes. This expedites the building of realtime, scalable apps while also cutting down on effort.

RethinkDB can be used for a number of different things: building realtime trading and optimization engines; simplifying the data infrastructure in multiplayer games to produce low latency, high throughput realtime interactions; building reactive web and mobile apps with a lot less effort, and so much more.