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="Common_Page|502" />
  </query-continue>
  <query>
    <pages>
      <page pageid="17" ns="0" title="Nevercenter 3D Modeling Wiki" />
      <page pageid="18" ns="0" title="General 3D Modeling Tutorials" />
      <page pageid="31" ns="0" title="Silo Tutorials" />
      <page pageid="478" ns="0" title="Tutorial Template" />
      <page pageid="495" ns="0" title="Boilerplate" />
      <page pageid="496" ns="0" title="Sticky Keys Video Tutorial" />
      <page pageid="498" ns="0" title="Character Modeling by Tony Jung" />
      <page pageid="499" ns="0" title="Subdivision Video Tutorial" />
      <page pageid="500" ns="0" title="Customization Video Tutorial" />
      <page pageid="501" ns="0" title="Selection Modes Video Tutorial" />
    </pages>
  </query>
</api>