You are looking at the HTML representation of the XML format.
HTML is good for debugging, but probably is not suitable for your application.
See complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query>
    <exturlusage>
      <eu pageid="8089" ns="0" title="Removing Wiki Spam" url="http://www.mediawiki.org/wiki/Anti-spam_features" />
      <eu pageid="2141" ns="10" title="Template:Author center" url="http://www.mediawiki.org/wiki/Extension:Word2MediaWikiPlus" />
      <eu pageid="4048" ns="0" title="Contributor Center" url="http://www.mediawiki.org/wiki/Extension:Word2MediaWikiPlus" />
      <eu pageid="8089" ns="0" title="Removing Wiki Spam" url="http://www.mediawiki.org/wiki/Manual:Combating_spam" />
      <eu pageid="8089" ns="0" title="Removing Wiki Spam" url="http://www.mediawiki.org/wiki/Manual:Combating_vandalism" />
      <eu pageid="2190" ns="0" title="Adding a calendar event" url="http://www.mediawiki.org/wiki/User:Hex2bit/Calendar" />
    </exturlusage>
  </query>
</api>