This is the web client for Discord, a highly expressive, object-based MMO engine written in JavaScript on top of Node.JS and MooTools.
require('discord-web').start({
"world_name" : "DiscordMUD",
"game_port" : 8000
}).listen(8080);
Change the variables accordingly, of course.
For an example world implementation of both the engine and the web client, see http://github.com/Yuffster/discord-example.