The Tor Browser / file revision

 <?xml version="1.0"?>

 <?xml-stylesheet href="chrome://global/skin/" type="text/css"?>

 <window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"

         onload="boom();">

 <script type="text/javascript">

 function boom()

 {

   var option = document.createElementNS("http://www.w3.org/1999/xhtml", "option");

   document.getElementById("tc").appendChild(option);

 }

 </script>

 <tree><treechildren id="tc"><hbox/></treechildren></tree>

 </window>