Ecosystems:
Java
See WebSocket with Jetty 8.
Simply run 'mvn' (tested with Maven3) and wait for Jetty to launch on localhost:9090
Now point your modern browser (e.g. Chromium) to http://localhost:9090/talkToServer.html
That's it...
There is only one Java class. Internally it simply dispatches the incoming message back to the sending client.
Have fun!