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>
    <alllinks galcontinue="Basic_XML_Writer|1478" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1" ns="0" title="Main Page" />
      <page pageid="1384" ns="0" title="Task Elements" />
      <page pageid="1433" ns="0" title="Pdf" />
      <page pageid="1434" ns="0" title="PDF Updated" />
      <page pageid="1441" ns="0" title="CSV Writer" />
      <page pageid="1442" ns="0" title="Properties Tree" />
      <page pageid="1445" ns="0" title="HTML Table Writer" />
      <page pageid="1448" ns="0" title="Custom Data Formatter Standard Option" />
      <page pageid="1476" ns="0" title="XML Document Writer" />
      <page pageid="1477" ns="0" title="XSLT Processor" />
    </pages>
  </query>
</api>