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="Bild_10_b.jpg|1055" />
  </query-continue>
  <query>
    <pages>
      <page pageid="843" ns="0" title="Mitsubishi Sigma" />
      <page pageid="856" ns="0" title="Mitsubishi Pajero" />
      <page pageid="1046" ns="0" title="Mitsubishi Concept SportSedan" />
      <page pageid="1146" ns="0" title="M@t Dunkels Sigma Seiten" />
      <page pageid="1234" ns="3" title="Benutzer Diskussion:Peter V6" />
      <page pageid="1297" ns="0" title="Mitsubishi Concept Sport Truck" />
      <page pageid="1490" ns="0" title="Mitsubishi Dion" />
      <page pageid="1552" ns="0" title="Mitsubishi Attrage" />
      <page pageid="1561" ns="0" title="Mitsubishi Thüringentreffen" />
      <page pageid="1608" ns="0" title="Mitsubishi Concept i" />
    </pages>
  </query>
</api>