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>
    <alllinks galcontinue="Downloadliste|1398" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1" ns="0" title="Hauptseite" />
      <page pageid="158" ns="0" title="Taufmatrik Hermersdorf M-24 2333 1701-1776:f074" />
      <page pageid="232" ns="0" title="Hermersdorf" />
      <page pageid="624" ns="4" title="Matriken:Aktuelle Ereignisse" />
      <page pageid="1103" ns="10" title="Vorlage:Taufmatrik Hermersdorf" />
      <page pageid="1376" ns="10" title="Vorlage:Abspann Hermersdorf" />
      <page pageid="1377" ns="0" title="Trauungsmatrik Hermersdorf M-24 2334 1777-1785:f001" />
      <page pageid="2598" ns="0" title="M00-1282 NOZ" />
      <page pageid="2604" ns="0" title="M00-1290 OZ" />
      <page pageid="2605" ns="0" title="M00-1291 OZ" />
    </pages>
  </query>
</api>