WebSocket

WebSocket
There is a security concern, so FF and Opera have disabled support by default
It is not recommended to use WebSockets at this time
If you wish to experiment with WebSockets in FF, you may do so by opening about:config and setting the network.websocket.enabled preference to true. You will also need to set the network.websocket.override-security-block preference to true in order to allow initializing a WebSocket connection.
WebSocket was to be implemented in Firefox 4, Google Chrome 4, Opera 11, and Safari 5, as well as the mobile version of Safari in iOS 4.2.[1] However, although present, support is now disabled by default in Firefox and Opera because of concerns over security vulnerabilities