NoPromises.js

/**************
 * Con promesas
 **************/

var promise = foo().then(function(){
  var promise = new Promise();
  asyncFunction(function(){
    // It has to know there is no need to merge it to a received object in order to
    // do this;
    var data = {key1:0x111};
    promise.done(data);
  })
  return promise;

}).then(function(data){
  var promise = new Promise();
  asyncFunction(function(){
    // It has to know the previous 
    // result was an OBJECT in order to do this
    data.key2 = 0x222;
    promise.done(data);
  })
  return promise;  

},function(err, data, promise){
  if(err) data.error = true;
  promise.done(data);

}).parallel(function(data){
  var promise = new Promise();
  asyncFunction(function(){
    data.key2 += 0x333; 
    promise.done(data);
  });
  return promise;

}).parallel(function(data){
  var promise.done(data);
  asyncFunction(function(){
    data.key2 += 0x444; 
    promise.done(data);
  })    
  return promise;
});

promise.then(function(){
  console.log("Por Fin!");
});


/**************
 * Sin promesas
 **************/

foo(function(){

  var data = {};

  asyncFunction(function(){
    data.key1 = 0x111;

    asyncFunction(function(err){
      if(err){
        data.error = true;        
        return;
      }
      data.key2 = 0x222; 
      parallel();
    });
  });

  var parallel = function(){

    var count = 0;

    asyncFunction(function(){
      data.key2 += 0x333;
      end();
    });

    asyncFunction(function(){
      data.key2 += 0x444;
      end();
    });

    var end = function(){
      if(++count === 2)
        console.log("Fin")
    }
  }
});