Sockjs is a browser javascript library that provides a websocket-like object. sockjs gives you a coherent, cross-browser, javascript api which creates a low latency, full duplex, cross-domain communication channel between the browser and the web server.

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 protocol, for example behind restrictive corporate proxies.