You are looking at the HTML representation of the XML format.
HTML is good for debugging, but probably is not suitable for your application.
See complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query-continue>
    <allimages gaifrom="4D OpenSim Manager.jpg" />
  </query-continue>
  <query>
    <pages>
      <page ns="6" title="File:3152.gif" missing="" />
      <page pageid="2156" ns="6" title="File:12345.JPG" />
      <page pageid="681" ns="6" title="File:2cg home 003 001.jpg" />
      <page pageid="682" ns="6" title="File:2cg home 003 014.jpg" />
      <page pageid="1271" ns="6" title="File:2nd-birthday-port-edward1.jpg" />
      <page pageid="1266" ns="6" title="File:2nd-birthday-schwarzle-welle1.jpg" />
      <page pageid="1267" ns="6" title="File:2nd-birthday-schwarzle-welle2.jpg" />
      <page pageid="1268" ns="6" title="File:2nd-birthday-schwarzle-welle3.jpg" />
      <page pageid="1269" ns="6" title="File:2nd-birthday-schwarzle-welle4.jpg" />
      <page pageid="1270" ns="6" title="File:2nd-birthday-schwarzle-welle5.jpg" />
    </pages>
  </query>
</api>