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="Skifteprotokol" />
  </query-continue>
  <query>
    <pages>
      <page pageid="308" ns="0" title="Brønderslev Sogn" />
      <page pageid="299" ns="0" title="Frederikshavn Sogn" />
      <page pageid="1239" ns="0" title="Holmsland Klit Sogn" />
      <page pageid="70" ns="0" title="Kirkebog" />
      <page pageid="145" ns="0" title="Knuthenborg Hovedgård" />
      <page pageid="77" ns="0" title="Lægdsrulle" />
      <page pageid="221" ns="0" title="Næstsøskendebarn" />
      <page pageid="192" ns="0" title="Pot (rummål)" />
      <page pageid="51" ns="0" title="Rigsrådet (1855)" />
      <page pageid="1488" ns="0" title="Skanderup Sogn (Skanderborg Amt)" />
    </pages>
  </query>
</api>