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="Draft|2004" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1571" ns="10" title="Template:Download" />
      <page pageid="1577" ns="0" title="Tram depot proposals" />
      <page pageid="1602" ns="0" title="Effects of single-site plan" />
      <page pageid="1613" ns="0" title="UDP" />
      <page pageid="1624" ns="0" title="Role of Site 63P" />
      <page pageid="1667" ns="0" title="Councillor&#039;s briefing pack" />
      <page pageid="1675" ns="0" title="Croydon tram depot" />
      <page pageid="2003" ns="0" title="Bellenden Residents Group" />
      <page pageid="2108" ns="0" title="Archives" />
      <page pageid="2659" ns="0" title="Peckham Rye Station stages" />
    </pages>
  </query>
</api>