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>
    <allcategories>
      <c size="17" pages="16" files="0" subcats="1" xml:space="preserve">NFSUnlimited.net</c>
      <c size="29" pages="29" files="0" subcats="0" xml:space="preserve">NFSUnlimited.net Showroom Challenges</c>
      <c size="284" pages="265" files="0" subcats="19" xml:space="preserve">Need for Speed</c>
      <c size="16" pages="16" files="0" subcats="0" xml:space="preserve">Need for Speed Carbon</c>
      <c size="40" pages="40" files="0" subcats="0" xml:space="preserve">Need for Speed Cars</c>
      <c size="8" pages="8" files="0" subcats="0" xml:space="preserve">Need for Speed Cheats</c>
      <c size="5" pages="5" files="0" subcats="0" xml:space="preserve">Need for Speed FAQs</c>
      <c size="5" pages="5" files="0" subcats="0" xml:space="preserve">Need for Speed Hot Pursuit</c>
      <c size="10" pages="10" files="0" subcats="0" xml:space="preserve">Need for Speed Hot Pursuit 2</c>
      <c size="5" pages="5" files="0" subcats="0" xml:space="preserve">Need for Speed Hot Pursuit 2010</c>
    </allcategories>
  </query>
  <query-continue>
    <allcategories acfrom="Need for Speed Most Wanted" />
  </query-continue>
</api>