Dnode - language agnostic asynchronous RPC built on socket.io (thechangelog.com)

  var dnode = require('dnode')
  dnode(function(client){
    this.is = function(cb){client.what(function(data){cb(data+' is awesome!')})}
  }).listen(3003).on('ready', function(){
    dnode({what:function(cb){cb('dnode')}}).connect(3003,function(server){
      server.is(function(data){console.log(data)})
    })
  })