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="204" ns="0" title="Evil creatures" />
      <page pageid="244" ns="0" title="Fay Short 01" />
      <page pageid="62" ns="0" title="Lindora" />
      <page pageid="54" ns="0" title="Outer Fire" />
      <page pageid="56" ns="0" title="Solid-clouds" />
      <page pageid="125" ns="0" title="The Fayrie" />
      <page pageid="110" ns="0" title="The Wonderbuss" />
      <page pageid="126" ns="0" title="The Zarth" />
      <page pageid="33" ns="0" title="TwinWorld" />
    </pages>
  </query>
</api>