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="50" ns="0" title="中西修" />
      <page pageid="53" ns="0" title="緒方薫" />
      <page pageid="38" ns="0" title="踊る大捜査線 THE MOVIE3 ヤツらを解放せよ!" />
      <page pageid="164" ns="0" title="長瀬国博" />
    </pages>
  </query>
</api>