Probably the main weakness of most Web applications is their uni-directional nature: a server can send data to the client only as a reply to his request. A server cannot initiate data sending to the client. And if something happens on a server, it has to wait for the client request, instead of notifying the client immediately.
Comet is a Web application architecture with bi-directional communication, when Client and Server are on equal rights, both being able to initiate data sending. Thus, if a Web application supports Comet architecture it becomes very close to conventional desktop (e.g. Windows) applications.
There are several approaches to implementing Comet, including Java applets and Flash applications running inside a client browser. Microsoft Silverlight-based Comet solutions are surely to appear soon and will be of great interest!
For more info see Read More »