You are looking at the HTML representation of the XML format.
HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format.
To see the non HTML representation of the XML format, set format=xml.
See the complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query-continue>
    <allimages gaicontinue="Baden-Baden_14_Theater.jpg" />
  </query-continue>
  <query>
    <pages>
      <page pageid="97" ns="6" title="File:180px-VDE Logo 4c.png" />
      <page pageid="88" ns="6" title="File:600px-Springer Science+Business Media S.A. logo.svg.png" />
      <page pageid="48" ns="6" title="File:Baden-Baden 01 Stadtansicht.jpg" />
      <page pageid="49" ns="6" title="File:Baden-Baden 03 Stadtansicht.jpg" />
      <page pageid="51" ns="6" title="File:Baden-Baden 04 Kurhaus.jpg" />
      <page pageid="52" ns="6" title="File:Baden-Baden 07 Casino.jpg" />
      <page pageid="54" ns="6" title="File:Baden-Baden 09 Lichtentaler Allee.jpg" />
      <page pageid="55" ns="6" title="File:Baden-Baden 10 Lichtentaler Allee.jpg" />
      <page pageid="56" ns="6" title="File:Baden-Baden 11 Caracalla.jpg" />
      <page pageid="57" ns="6" title="File:Baden-Baden 13 Museum Frieder Burda.jpg" />
    </pages>
  </query>
</api>