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="CharacterNew|110" />
  </query-continue>
  <query>
    <pages>
      <page pageid="101" ns="0" title="Nanoha Takamachi" />
      <page pageid="102" ns="0" title="Fate T. Waldia" />
      <page pageid="103" ns="0" title="Precia Testarossa" />
      <page pageid="104" ns="0" title="Yuuno Scrya" />
      <page pageid="105" ns="0" title="Arf" />
      <page pageid="106" ns="0" title="Chrono Harlaown" />
      <page pageid="107" ns="0" title="Nagisa Misumi" />
      <page pageid="108" ns="0" title="Honoka Yukishiro" />
      <page pageid="109" ns="0" title="Pisard" />
      <page pageid="242" ns="10" title="Template:RTable" />
    </pages>
  </query>
</api>