Articles introduced the server push mechanism on html
Traditional Comet mechanism
http://www.ibm.com/developerworks/web/library/wa-reverseajax1/index.html
HTML5 Websocket
http://www.ibm.com/developerworks/web/library/wa-reverseajax2/index.html
Java server side solution for comet/websocket
http://www.ibm.com/developerworks/web/library/wa-reverseajax3/index.html
Java framework for comet/websocket
http://www.ibm.com/developerworks/web/library/wa-reverseajax4/index.html