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-continue>
    <allimages gaifrom="ApagadosWM.JPG" />
  </query-continue>
  <query>
    <pages>
      <page pageid="455" ns="6" title="File:1.jpg" />
      <page pageid="392" ns="6" title="File:123.gif" />
      <page pageid="294" ns="6" title="File:Add object(0).jpg" />
      <page pageid="290" ns="6" title="File:Add object(1).jpg" />
      <page pageid="291" ns="6" title="File:Add object(2).jpg" />
      <page pageid="292" ns="6" title="File:Add object(3).jpg" />
      <page pageid="293" ns="6" title="File:Add object(4).jpg" />
      <page pageid="398" ns="6" title="File:Add place to this building.png" />
      <page pageid="50" ns="6" title="File:Ambox warning yellow.png" />
      <page pageid="458" ns="6" title="File:Aninhado.JPG" />
    </pages>
  </query>
</api>