jimmyrcom/HTML5-Canvas-Old-School-RPG-Map-with-Erlang-Websockets-Chat

You can make MMOs now using html thanks to google. See the link for what it does. The client is pure HTML5, the server here is erlang.

Check it out here:
http://rp.eliteskills.com/html5.php

It's a basic old school style RPG MAP that supports multiple users using HTML5 Websockets for the client and erlang for the server.