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>
    <allredirects garcontinue="Https://wiki.piratenpartei.de/Benutzer:Puck.152|6731" />
  </query-continue>
  <query>
    <pages>
      <page pageid="120" ns="0" title="LV:TH" />
      <page pageid="557" ns="0" title="Landesverband Thüringen" />
      <page pageid="1073" ns="0" title="TH:BPT Bingen Piratomobil" />
      <page pageid="1607" ns="0" title="DE:Gesetze" />
      <page pageid="2937" ns="0" title="Fragen und Antworten" />
      <page pageid="3372" ns="0" title="3. Treffen 02.03.2012" />
      <page pageid="3382" ns="0" title="Altenburg" />
      <page pageid="4728" ns="0" title="TH:Landesverband Thüringen" />
      <page pageid="5207" ns="0" title="TH:Landesparteitag 2012.2/Antragsportal/Satzungsänderungsantrag - 008" />
      <page pageid="7058" ns="0" title="TH:Kreisparteitag 2013.1/Antragsportal/Sonstiger Antrag - 002" />
    </pages>
  </query>
</api>