<script type="text/javascript" src="/javascripts/scriptaculous.js?load=builder,effects"></script>

<script type="text/javascript" src="/javascripts/scriptaculous.js?load=builder,effects"></script>
<script type="text/javascript" src="/javascripts/builder.js"></script>
<script type="text/javascript" src="/javascripts/effects.js"></script>

load: function() {
    alert('In the load function!');
    ...rest of code here...

$A(document.getElementsByTagName("script")).findAll( function(s) {
      return (s.src && s.src.match(/scriptaculous.js(?.*)?$/))
    }).each( function(s) {
      var path = s.src.replace(/scriptaculous.js(?.*)?$/,'');
      var includes = s.src.match(/?.*load=([a-z,]*)/);
      (includes ? includes[1] : 'builder,effects,dragdrop,controls,slider,sound').split(',').each(
       function(include) { Scriptaculous.require(path+include+'.js') });
    });

var includes = s.src.match(/?.*load=([a-z,]*)/);
alert(includes[0] + ' ' + includes[1]);

<script type="text/javascript" src="/javascripts/scriptaculous.js"></script>
<script type="text/javascript" src="/javascripts/builder.js"></script>
<script type="text/javascript" src="/javascripts/effects.js"></script>