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="7" ns="0" title="Valantia" />
      <page pageid="8" ns="0" title="Velantia" />
      <page pageid="78" ns="0" title="Clavis Bern" />
      <page pageid="98" ns="0" title="Part 8: Breaking Bad" />
      <page pageid="119" ns="0" title="Part 15: On the Open Ocean" />
      <page pageid="151" ns="0" title="Part 30: The Temple of Hanuman" />
      <page pageid="193" ns="0" title="Part 4: Tomb Raiders" />
    </pages>
  </query>
</api>