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="AddHostRecordsAttr.png" />
  </query-continue>
  <query>
    <pages>
      <page pageid="328" ns="6" title="File:1API domainlöschung ch de.pdf" />
      <page pageid="67" ns="6" title="File:531x235 info.gif" />
      <page pageid="1294" ns="6" title="File:AM TransferTrade.pdf" />
      <page pageid="413" ns="6" title="File:AM dotAM Transfer Trade.pdf" />
      <page pageid="595" ns="6" title="File:Ac.jpg" />
      <page pageid="1409" ns="6" title="File:Accountant.png" />
      <page pageid="841" ns="6" title="File:Actor.png" />
      <page pageid="1326" ns="6" title="File:AddCustomNameservers.png" />
      <page pageid="1325" ns="6" title="File:AddDefaultNameservers.png" />
      <page pageid="1328" ns="6" title="File:AddHostRecords.png" />
    </pages>
  </query>
</api>