Language-agnostic real-time messaging server and its friends
Machine-to-machine instant messaging platform for the internet of things #IoT
Python client for Google Cloud Messaging for Android (GCM)
An observable µService bus .NET library that wraps the complexities of your particular transport in simple Rx based interfaces.
Swift Client Library for the Faye Pub-Sub messaging server (http://faye.jcoglan.com/)
A simple, easy to use asynchronous messaging framework for .NET
dynamic attributed-based publish/subscribe messaging system