https://gist.github.com/1034095 を CoffeeScript で書いてみた

chat.coffee

# This program is free software. It comes without any warranty, to
# the extent permitted by applicable law. You can redistribute it
# and/or modify it under the terms of the Do What The Fuck You Want
# To Public License, Version 2, as published by Sam Hocevar. See
# http://sam.zoy.org/wtfpl/COPYING for more details.
sys    = require 'sys'
opts   = require 'opts'
ws     = require 'websocket-server'
redis  = require 'redis'
server = ws.createServer()

subscriber = redis.createClient 6379, 'localhost'
publisher  = redis.createClient 6379, 'localhost'

opts.parse([
  {
    'short':       'p',
    'long':        'port',
    'description': 'WebSocket Port',
    'value':       true,
    'required':    true
  }
])

subscriber.on "error", (err) ->
  sys.debug err

publisher.on "error", (err) ->
  sys.debug err

subscriber.subscribe "chat"
subscriber.on "message", (channel, message) ->
  sys.puts message
  server.broadcast message

server.addListener "connection", (connection) ->
  sys.puts "client connected: " + connection.id

  connection.addListener "message", (message) ->
    publisher.publish "chat", message

server.addListener "close", (connection) ->
  sys.puts "client disconnected: " + connection.id

server.listen opts.get('port')