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>
    <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">Casa Don Orione - Trebaseleghe</ns>
      <ns id="5" case="first-letter" subpages="" canonical="Project talk" xml:space="preserve">Discussioni Casa Don Orione - Trebaseleghe</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>
      <ns id="102" case="first-letter" canonical="Proprietà" xml:space="preserve">Proprietà</ns>
      <ns id="103" case="first-letter" subpages="" canonical="Discussione proprietà" xml:space="preserve">Discussione proprietà</ns>
      <ns id="106" case="first-letter" canonical="Form" xml:space="preserve">Modulo</ns>
      <ns id="107" case="first-letter" subpages="" canonical="Form talk" xml:space="preserve">Discussione modulo</ns>
      <ns id="108" case="first-letter" canonical="Concetto" xml:space="preserve">Concetto</ns>
      <ns id="109" case="first-letter" canonical="Discussione concetto" xml:space="preserve">Discussione concetto</ns>
      <ns id="170" case="first-letter" canonical="Filter" xml:space="preserve">Filter</ns>
      <ns id="171" case="first-letter" subpages="" canonical="Filter talk" xml:space="preserve">Filter talk</ns>
      <ns id="200" case="first-letter" canonical="UserWiki" xml:space="preserve">UserWiki</ns>
      <ns id="201" case="first-letter" canonical="UserWiki talk" xml:space="preserve">UserWiki talk</ns>
      <ns id="202" case="first-letter" canonical="User profile" xml:space="preserve">User profile</ns>
      <ns id="203" case="first-letter" canonical="User profile talk" xml:space="preserve">User profile talk</ns>
      <ns id="210" case="first-letter" subpages="" canonical="Eventi" content="" nonincludable="" xml:space="preserve">Eventi</ns>
      <ns id="211" case="first-letter" subpages="" canonical="Discussione Eventi" content="" nonincludable="" xml:space="preserve">Discussione Eventi</ns>
      <ns id="212" case="first-letter" subpages="" canonical="Persone" content="" nonincludable="" xml:space="preserve">Persone</ns>
      <ns id="213" case="first-letter" subpages="" canonical="Discussione Persone" content="" nonincludable="" xml:space="preserve">Discussione Persone</ns>
      <ns id="214" case="first-letter" subpages="" canonical="Famiglie" content="" nonincludable="" xml:space="preserve">Famiglie</ns>
      <ns id="215" case="first-letter" subpages="" canonical="Discussione Famiglie" content="" nonincludable="" xml:space="preserve">Discussione Famiglie</ns>
      <ns id="216" case="first-letter" subpages="" canonical="Luoghi" content="" nonincludable="" xml:space="preserve">Luoghi</ns>
      <ns id="217" case="first-letter" subpages="" canonical="Discussione Luoghi" content="" nonincludable="" xml:space="preserve">Discussione Luoghi</ns>
      <ns id="218" case="first-letter" subpages="" canonical="Area Privata" content="" nonincludable="" xml:space="preserve">Area Privata</ns>
      <ns id="219" case="first-letter" subpages="" canonical="Discussione Area Privata" content="" nonincludable="" xml:space="preserve">Discussione Area Privata</ns>
      <ns id="220" case="first-letter" subpages="" canonical="Contatti" content="" nonincludable="" xml:space="preserve">Contatti</ns>
      <ns id="221" case="first-letter" subpages="" canonical="Discussione Contatti" content="" nonincludable="" xml:space="preserve">Discussione Contatti</ns>
      <ns id="222" case="first-letter" subpages="" canonical="Forms" content="" xml:space="preserve">Forms</ns>
      <ns id="224" case="first-letter" subpages="" canonical="Artisti" content="" nonincludable="" xml:space="preserve">Artisti</ns>
      <ns id="225" case="first-letter" subpages="" canonical="Discussione Artisti" content="" nonincludable="" xml:space="preserve">Discussione Artisti</ns>
      <ns id="226" case="first-letter" subpages="" canonical="Ringraziamenti" content="" nonincludable="" xml:space="preserve">Ringraziamenti</ns>
      <ns id="227" case="first-letter" subpages="" canonical="Discussione Ringraziamenti" content="" nonincludable="" xml:space="preserve">Discussione Ringraziamenti</ns>
      <ns id="228" case="first-letter" subpages="" canonical="Pubblicazioni" content="" nonincludable="" xml:space="preserve">Pubblicazioni</ns>
      <ns id="229" case="first-letter" subpages="" canonical="Discussione Pubblicazioni" content="" nonincludable="" xml:space="preserve">Discussione Pubblicazioni</ns>
      <ns id="274" case="first-letter" canonical="Widget" xml:space="preserve">Widget</ns>
      <ns id="275" case="first-letter" subpages="" canonical="Widget talk" xml:space="preserve">Widget talk</ns>
    </namespaces>
  </query>
</api>