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-continue>
    <allfileusages gafcontinue="Basingstoke-discovery-centre-2.jpg|104" />
  </query-continue>
  <query>
    <pages>
      <page pageid="2140" ns="0" title="Paměť a její centra" />
      <page pageid="2222" ns="0" title="Usir" />
      <page pageid="2271" ns="0" title="Sokar" />
      <page pageid="2376" ns="0" title="Konference Moc emocí" />
      <page pageid="2691" ns="0" title="Ba" />
      <page pageid="2943" ns="0" title="Uživatelské rozhraní (user interface)" />
      <page pageid="3289" ns="0" title="Arkologie" />
      <page pageid="3999" ns="0" title="Charles Babbage" />
      <page pageid="5998" ns="0" title="15. Pozorování – typy, možnosti a meze" />
      <page pageid="7303" ns="0" title="Uživatelské rozhraní rešeršních systémů" />
    </pages>
  </query>
</api>