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" case="first-letter" canonical="Media" xml:space="preserve">Media</ns>
      <ns id="-1" case="first-letter" canonical="Special" xml:space="preserve">Speciale</ns>
      <ns id="0" case="first-letter" content="" xml:space="preserve" />
      <ns id="1" case="first-letter" subpages="" canonical="Talk" xml:space="preserve">Discussione</ns>
      <ns id="2" case="first-letter" subpages="" canonical="User" xml:space="preserve">Utente</ns>
      <ns id="3" case="first-letter" subpages="" canonical="User talk" xml:space="preserve">Discussioni utente</ns>
      <ns id="4" case="first-letter" canonical="Project" xml:space="preserve">C.I.S.A.R. RadioWiki</ns>
      <ns id="5" case="first-letter" subpages="" canonical="Project talk" xml:space="preserve">Discussioni C.I.S.A.R. RadioWiki</ns>
      <ns id="6" case="first-letter" canonical="File" xml:space="preserve">File</ns>
      <ns id="7" case="first-letter" subpages="" canonical="File talk" xml:space="preserve">Discussioni file</ns>
      <ns id="8" case="first-letter" subpages="" canonical="MediaWiki" xml:space="preserve">MediaWiki</ns>
      <ns id="9" case="first-letter" subpages="" canonical="MediaWiki talk" xml:space="preserve">Discussioni MediaWiki</ns>
      <ns id="10" case="first-letter" canonical="Template" xml:space="preserve">Template</ns>
      <ns id="11" case="first-letter" subpages="" canonical="Template talk" xml:space="preserve">Discussioni template</ns>
      <ns id="12" case="first-letter" canonical="Help" xml:space="preserve">Aiuto</ns>
      <ns id="13" case="first-letter" subpages="" canonical="Help talk" xml:space="preserve">Discussioni aiuto</ns>
      <ns id="14" case="first-letter" canonical="Category" xml:space="preserve">Categoria</ns>
      <ns id="15" case="first-letter" subpages="" canonical="Category talk" xml:space="preserve">Discussioni categoria</ns>
    </namespaces>
  </query>
</api>