Cometd (aka Bayeux) - Jetty
docs.codehaus.org/display/JETTY/Cometd+(aka+Bayeux)
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
Jetty includes a servlet implementation of the Bayeux protocol of the CometD project from the Dojo Foundation.
CometD is a message bus for Ajax web applications that allows multi channel messaging between client and server - and more importantly - between server and client. The paradigm is publish/subscribe to named channels.