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>
    <alltransclusions gatcontinue="Kontakt|8" />
  </query-continue>
  <query>
    <pages>
      <page pageid="6" ns="0" title="Eingeschränkter Internetzugang in Gefängnissen" />
      <page pageid="1185" ns="0" title="Outlook Zertifikat einbinden" />
      <page pageid="1632" ns="0" title="Exchange Funktionsaccount in Outlook einrichten" />
      <page pageid="1686" ns="0" title="E-Mail Security" />
      <page pageid="1873" ns="0" title="Postmaster" />
      <page pageid="2362" ns="0" title="Apple Mail" />
      <page pageid="3030" ns="14" title="Kategorie:Thunderbird" />
      <page pageid="3069" ns="0" title="Apple Mail Funktionspostfach fuer nicht Studierende" />
      <page pageid="3084" ns="10" title="Vorlage:MediaWiki-Button" />
      <page pageid="3091" ns="0" title="Outlook Zertifikat Funktionspostfach einbinden" />
    </pages>
  </query>
</api>