gevent - gevent is a coroutine -based Python networking library that uses greenlet to provide a high-level...

Socket.io - Realtime application framework (Node.JS server)

Pusher - Pusher is a hosted API for quickly, easily and securely adding scalable realtime functionality via WebSockets to web and mobile apps.

eventlet - Eventlet is a concurrent networking library for Python that allows you to change how you run your...

SignalR - SignalR is a server-side software system designed for writing scalable Internet applications, notably web servers.

greenlet - Lightweight in-process concurrent programming