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>
    <namespaces>
      <ns id="-2" canonical="Media" xml:space="preserve">Media</ns>
      <ns id="-1" canonical="Special" xml:space="preserve">Special</ns>
      <ns id="0" xml:space="preserve" />
      <ns id="1" subpages="" canonical="Talk" xml:space="preserve">Talk</ns>
      <ns id="2" subpages="" canonical="User" xml:space="preserve">User</ns>
      <ns id="3" subpages="" canonical="User talk" xml:space="preserve">User talk</ns>
      <ns id="4" canonical="Project" xml:space="preserve">Scienticity</ns>
      <ns id="5" subpages="" canonical="Project talk" xml:space="preserve">Scienticity talk</ns>
      <ns id="6" canonical="File" xml:space="preserve">File</ns>
      <ns id="7" subpages="" canonical="File talk" xml:space="preserve">File talk</ns>
      <ns id="8" canonical="MediaWiki" xml:space="preserve">MediaWiki</ns>
      <ns id="9" subpages="" canonical="MediaWiki talk" xml:space="preserve">MediaWiki talk</ns>
      <ns id="10" canonical="Template" xml:space="preserve">Template</ns>
      <ns id="11" subpages="" canonical="Template talk" xml:space="preserve">Template talk</ns>
      <ns id="12" canonical="Help" xml:space="preserve">Help</ns>
      <ns id="13" subpages="" canonical="Help talk" xml:space="preserve">Help talk</ns>
      <ns id="14" canonical="Category" xml:space="preserve">Category</ns>
      <ns id="15" subpages="" canonical="Category talk" xml:space="preserve">Category talk</ns>
    </namespaces>
  </query>
</api>