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="23" ns="0" title="Dramatic Persona -- Preservers of the Tribe" />
      <page pageid="24" ns="0" title="Dramatis Persona -- Living Members of the Tribe" />
      <page pageid="25" ns="0" title="Dramatis Persona -- Wrapstuffed Members of the Tribe" />
      <page pageid="26" ns="0" title="Dramatis Persona -- Deceased Members of the Tribe" />
      <page pageid="553" ns="0" title="Dramatis Personae -- Preservers of the Tribe" />
      <page pageid="764" ns="0" title="Sending Distances" />
    </pages>
  </query>
</api>