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>
    <allfileusages gafcontinue="Construction.png|1473" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1415" ns="0" title="WAP Director" />
      <page pageid="1433" ns="0" title="Carl (C.J.) Nelson" />
      <page pageid="1438" ns="0" title="2005 EOYB" />
      <page pageid="1439" ns="0" title="2003 EOYB" />
      <page pageid="1443" ns="0" title="Current events" />
      <page pageid="1460" ns="0" title="IAEA" />
      <page pageid="1462" ns="0" title="DISEC" />
      <page pageid="1467" ns="0" title="WorldMUN 2007" />
      <page pageid="1469" ns="0" title="UNDP" />
      <page pageid="1656" ns="0" title="25th Year Anniversary" />
    </pages>
  </query>
</api>