horizon
Horizon is a realtime, open-source backend for JavaScript apps
...While technologies like RethinkDB and WebSocket make it possible to build engaging realtime apps, empirically there is still too much friction for most developers. Building realtime apps now requires understanding and manually orchestrating multiple systems across the software stack, understanding distributed stream processing, and learning how to deploy and scale realtime systems. The learning curve is quite steep, and most of the initial work involves boilerplate code that is far removed from the primary task of building a realtime app.