Sockjs can be used as an alternative to official websocket plugin or socket.io.
As we wait for a Socket.io 1.0 I've decided to put my efforts on SockJS plugin. Because of the design of sockjs library, the plugin is almost identical to the official websocket plugin, but enables you to use all advantages of sockjs. There's more work to be done, if you are using this plugin, please report back on how did it go.
From the official SockJS readme:
Under the hood SockJS tries to use native WebSockets first. If that fails it can use a variety of browser-specific transport protocols and presents them through WebSocket-like abstractions.
SockJS is intended to work for all modern browsers and in environments which don't support WebSocket protcol, for example behind restrictive corporate proxies.
You can find a simple test demo here, and the plugin here.
If you find any bugs, or have some ideas on how to improve this plugin, please head over here
For more info on SockJS, check here.