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>
    <allfileusages gafcontinue="Bosper_Lassan.png|53" />
  </query-continue>
  <query>
    <pages>
      <page pageid="34" ns="0" title="Gero Fuxfell" />
      <page pageid="57" ns="0" title="Blitzsplitter" />
      <page pageid="164" ns="0" title="Berkwin Mehltheuer" />
      <page pageid="185" ns="0" title="Birkenhaut" />
      <page pageid="387" ns="0" title="Bardo von Rossberg" />
      <page pageid="432" ns="0" title="Ankunft in Riva und Kampf gegen namenloses Übel" />
      <page pageid="454" ns="0" title="Ein Finale in Riva" />
      <page pageid="455" ns="0" title="Arlingen" />
      <page pageid="523" ns="0" title="Baltram Fuxfell" />
      <page pageid="595" ns="0" title="Benerim" />
    </pages>
  </query>
</api>