One of the most exiting new things in HTML5 is the ability to start pushing data from the server to the client. Traditionally web applications have depended on clients requesting data from the server. And this is fine in most applications. However there are lots of cases when you might want to push events to the client as soon as they happen and not wait for a client to query for them. For example a stock broker application requires traders to know about stock price changes as soon as they happen, alerting the trader 5 minutes after the fact is no good. Traditionally this could be done using long polling. This technique can be quite effective but a bit troublesome in getting to work reliably. The long polling mechanism has actually been formalized in the HTML5 specs as well with Server-sent DOM events and the the EventSource object. While quite effective, and relatively well supported, there is a newer technique of WebSockets that is far more capable.  No more HTTP traffic The WebSockets standard has one slight drawback though in that is is no longer using HTTP traffic. Where the...