cometD

cometD is a scalable HTTP-based event routing bus that uses techniques known as Comet. cometD is an open-source project that includes the Bayeux protocol specification, Dojo Toolkit-based JavaScript Comet libraries, and a collection of scalable HTTP-based event servers written in Python, Java, and Perl.

cometD improves real-time user experience, and the Bayeux protocol makes it easy to choose from and use a variety of Comet servers. Applications built using the Dojo Toolkit can be deployed on any Bayeux-compliant server.