comet

http://pokein.codeplex.com/SourceControl/latest#Comet/PokeIn.js

http://www.tuicool.com/articles/ErYN3y

http://www.cnblogs.com/hebeiDGL/archive/2012/09/28/2707027.html

http://www.codeproject.com/Articles/617611/Using-WebSocket-in-NET-4-5-Part-1