Asynchronous code injection

buysellads.html

<script type="text/javascript">
(function(){
  var bsa = document.createElement('script');
     bsa.type = 'text/javascript';
     bsa.async = true;
     bsa.src = '//s3.buysellads.com/ac/bsa.js';
  (document.getElementsByTagName('head')[0]||document.getElementsByTagName('body')[0]).appendChild(bsa);
})();
</script>

classic.html

<script>
  var resource = document.createElement('script'); 
  resource.src = "//third-party.com/resource.js";
  var script = document.getElementsByTagName('script')[0];
  script.parentNode.insertBefore(resource, script);
</script>

classic.wrapped.js

(function(d, t) {
    var g = d.createElement(t),
        s = d.getElementsByTagName(t)[0];
    g.src = '//third-party.com/resource.js';
    s.parentNode.insertBefore(g, s);
}(document, 'script'));

deck.html

<!-- N.B. Not async! -->
<script type="text/javascript">
//<![CDATA[
(function(id) {
 document.write('<script type="text/javascript" src="' +
   'http://connect.decknetwork.net/deck' + id + '_js.php?' +
   (new Date().getTime()) + '"></' + 'script>');
})("DF");
//]]>
</script>

facebook.html

<div id="fb-root"></div>
<script>(function(d, s, id) {
  var js, fjs = d.getElementsByTagName(s)[0];
  if (d.getElementById(id)) return;
  js = d.createElement(s); js.id = id;
  js.src = "//connect.facebook.net/en_US/all.js#xfbml=1&appId=200103733347528";
  fjs.parentNode.insertBefore(js, fjs);
}(document, 'script', 'facebook-jssdk'));</script>

html5.html

<script async src="http://third-party.com/resource.js"></script>

twitter.html

<a href="https://twitter.com/share" class="twitter-share-button">Tweet</a>
<script>!function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs");</script>

typekit.html

<script type="text/javascript">
  TypekitConfig = {
    kitId: 'abc1def'
  };
  (function() {
    var tk = document.createElement('script');
    tk.src = '//use.typekit.com/' + TypekitConfig.kitId + '.js';
    tk.type = 'text/javascript';
    tk.async = 'true';
    tk.onload = tk.onreadystatechange = function() {
      var rs = this.readyState;
      if (rs && rs != 'complete' && rs != 'loaded') return;
      try { Typekit.load(TypekitConfig); } catch (e) {}
    };
    var s = document.getElementsByTagName('script')[0];
    s.parentNode.insertBefore(tk, s);
  })();
</script>

withjquery.js

$.ajax({
  url: '//third-party.com/resource.js',
  dataType: 'script',
  cache: true, // otherwise will get fresh copy every page load
  success: function() {
    // script loaded, do stuff!
  }
}

yepnope.js

yepnope.injectJs("//third-party.com/resource.js", function () {
  // script loaded, do stuff!
});