title: Javascript - waiting for a number of asynchronous callbacks to return?
body: <p>What's the best way/library for handling multiple asynchronous callbacks? Right now, I have something like this:</p>
  
  <pre><code>_.each(stuff, function(thing){
     async(thing, callback);
  });
  </code></pre>
  
  <p>I need to execute some code after the callback has been fired for each element in <code>stuff</code>.</p>
  
  <p>What's the cleanest way to do this? I'm open to using libraries.</p>