simperium - Move data everywhere it's needed, instantly and automatically
gevent - gevent is a coroutine -based Python networking library that uses greenlet to provide a high-level...
GUN - Self-hosted Firebase.
Socket.io - Realtime application framework (Node.JS server)
PubNub - PubNub is a real-time messaging system for web and mobile apps that can handle API for all platforms and push messages to any device anywhere in the world in a fraction of a second without having to worry about proxies, firewalls or mobile drop-offs.
Lightstreamer - Lightstreamer is a server for delivering real-time messages to browser-based and mobile...