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>
    <pages>
      <page pageid="64" ns="6" title="File:Ambox content.png" />
      <page pageid="78" ns="6" title="File:Ambox move.png" />
      <page pageid="62" ns="6" title="File:Ambox notice.png" />
      <page pageid="79" ns="6" title="File:Ambox protection.png" />
      <page pageid="77" ns="6" title="File:Ambox speedy deletion.png" />
      <page pageid="80" ns="6" title="File:Edit clear.png" />
      <page pageid="1179" ns="6" title="File:Ferry xpress.jpg" />
      <page pageid="3149" ns="6" title="File:Traveliving.jpg" />
      <page pageid="3148" ns="6" title="File:Traveliving - a romantic &amp; practical guide.jpg" />
    </pages>
  </query>
</api>