answering from chris coyier's http://codepen.io/chriscoyier/pen/dKnpa?editors=001

f1.js

// the old way :/

$.ajax({
  url: "http://codepen.io/chriscoyier/pen/b2ad8b9a336845dd7b11d4bed34f4256.html",
  complete: function(resp) {
    
    // This HTML needs to be there first
    $("body").append(resp.responseText);
    
    // Because this script is going to do something with it.
    $.getScript("http://codepen.io/chriscoyier/pen/cee78be969f36ddb01de3d74fd46b451.js");
    
    // But that feels like it could be faster because why not do both requests right away but execute in order (or whatever).
  }
});

f2.js

// better, and more promise like... :)
// but, still "serial"... :(
$.ajax({
  url: "http://codepen.io/chriscoyier/pen/b2ad8b9a336845dd7b11d4bed34f4256.html"
})
.done(function(resp){
    // This HTML needs to be there first
    $("body").append(resp.responseText);
    
    // Because this script is going to do something with it.
    $.getScript("http://codepen.io/chriscoyier/pen/cee78be969f36ddb01de3d74fd46b451.js");
});

f3.js

// IF "cee78be969f36ddb01de3d74fd46b451.js" had a function 
// in it to call when you wanted it to apply, like `myScriptBegin()`,
// instead of automatically causing side effects on the page
// when it finishes loading, then you can do them in parallel.

// here's how you do THAT with asynquence:

ASQ()
// in asynquence, a gate is two or more things happening in
// parallel, and we have to wait for both to finish (in either
// order) before we move on
.gate(
	// one thing in parallel
	function(done){
		$.ajax({
			url: "http://codepen.io/chriscoyier/pen/b2ad8b9a336845dd7b11d4bed34f4256.html"
		})
		.then(done,done.fail);
	},
	function(done){
		$.getScript("http://codepen.io/chriscoyier/pen/cee78be969f36ddb01de3d74fd46b451.js")
		.then(done,done.fail);
	}
)
// this step will wait for the previous gate to finish before it goes on
.val(function(resp){
	// This HTML needs to be there first
	$("body").append(resp.responseText);
	
	// Because this script is going to do something with it.
	myScriptBegin(); // this is the function in your script that activates the page
})
.or(function(err){
	console.log("Oops, something broke: " + err);
});