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>
    <general mainpage="Hauptseite" base="http://medienvielfalt.zum.de/wiki/Hauptseite" sitename="Medienvielfalt-Wiki" generator="MediaWiki 1.21.2" phpversion="5.3.10-1ubuntu3.26" phpsapi="apache2handler" dbtype="mysql" dbversion="5.5.54-0ubuntu0.12.04.1-log" langconversion="" titleconversion="" linkprefix="" linktrail="/^([äöüßa-z]+)(.*)$/sDu" case="first-letter" rights="CC-BY-SA" lang="de" fallback8bitEncoding="windows-1252" writeapi="" timezone="Europe/Berlin" timeoffset="60" articlepath="/wiki/$1" scriptpath="" script="/index.php" variantarticlepath="" server="http://medienvielfalt.zum.de" wikiid="wikis-medienvielfalt" time="2024-12-21T19:00:04Z" maxuploadsize="134217728">
      <fallback>
        <lang code="en" />
      </fallback>
    </general>
    <namespaces>
      <ns id="-2" case="first-letter" canonical="Media" xml:space="preserve">Medium</ns>
      <ns id="-1" case="first-letter" canonical="Special" xml:space="preserve">Spezial</ns>
      <ns id="0" case="first-letter" subpages="" content="" xml:space="preserve" />
      <ns id="1" case="first-letter" subpages="" canonical="Talk" xml:space="preserve">Diskussion</ns>
      <ns id="2" case="first-letter" subpages="" canonical="User" xml:space="preserve">Benutzer</ns>
      <ns id="3" case="first-letter" subpages="" canonical="User talk" xml:space="preserve">Benutzer Diskussion</ns>
      <ns id="4" case="first-letter" subpages="" canonical="Project" xml:space="preserve">Medienvielfalt-Wiki</ns>
      <ns id="5" case="first-letter" subpages="" canonical="Project talk" xml:space="preserve">Medienvielfalt-Wiki Diskussion</ns>
      <ns id="6" case="first-letter" canonical="File" xml:space="preserve">Datei</ns>
      <ns id="7" case="first-letter" subpages="" canonical="File talk" xml:space="preserve">Datei Diskussion</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">MediaWiki Diskussion</ns>
      <ns id="10" case="first-letter" canonical="Template" xml:space="preserve">Vorlage</ns>
      <ns id="11" case="first-letter" subpages="" canonical="Template talk" xml:space="preserve">Vorlage Diskussion</ns>
      <ns id="12" case="first-letter" subpages="" canonical="Help" xml:space="preserve">Hilfe</ns>
      <ns id="13" case="first-letter" subpages="" canonical="Help talk" xml:space="preserve">Hilfe Diskussion</ns>
      <ns id="14" case="first-letter" canonical="Category" xml:space="preserve">Kategorie</ns>
      <ns id="15" case="first-letter" subpages="" canonical="Category talk" xml:space="preserve">Kategorie Diskussion</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 Diskussion</ns>
      <ns id="310" case="first-letter" canonical="Group" xml:space="preserve">Group</ns>
      <ns id="311" case="first-letter" canonical="Group talk" xml:space="preserve">Group talk</ns>
      <ns id="420" case="first-letter" canonical="Layer" xml:space="preserve">Layer</ns>
      <ns id="421" case="first-letter" canonical="Layer talk" xml:space="preserve">Layer Diskussion</ns>
      <ns id="460" case="case-sensitive" canonical="Campaign" defaultcontentmodel="Campaign" xml:space="preserve">Campaign</ns>
      <ns id="461" case="case-sensitive" canonical="Campaign talk" xml:space="preserve">Campaign talk</ns>
      <ns id="710" case="first-letter" canonical="TimedText" xml:space="preserve">TimedText</ns>
      <ns id="711" case="first-letter" canonical="TimedText talk" xml:space="preserve">TimedText talk</ns>
    </namespaces>
    <namespacealiases>
      <ns id="6" xml:space="preserve">File</ns>
      <ns id="7" xml:space="preserve">File talk</ns>
      <ns id="6" xml:space="preserve">Image</ns>
      <ns id="7" xml:space="preserve">Image talk</ns>
      <ns id="6" xml:space="preserve">Bild</ns>
      <ns id="7" xml:space="preserve">Bild Diskussion</ns>
      <ns id="2" xml:space="preserve">Benutzerin</ns>
      <ns id="3" xml:space="preserve">Benutzerin Diskussion</ns>
    </namespacealiases>
    <statistics pages="1052" articles="204" views="4834273" edits="7110" images="409" users="45" activeusers="0" admins="10" jobs="0" />
  </query>
</api>