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>
    <allpages>
      <p pageid="396" ns="0" title="Beruška jasle-škôlka" />
      <p pageid="242" ns="0" title="Britská medzinárodná škola" />
      <p pageid="158" ns="0" title="Britská medzinárodná škola" />
      <p pageid="289" ns="0" title="Burza detských potrieb" />
      <p pageid="50" ns="0" title="Burza detských potrieb" />
      <p pageid="290" ns="0" title="Burza práce" />
      <p pageid="60" ns="0" title="Burza práce" />
      <p pageid="135" ns="0" title="Centrum starostlivosti AAK" />
      <p pageid="376" ns="0" title="DC Kvietok Blumentálska" />
      <p pageid="249" ns="0" title="DC Sloník Humenská Košice" />
    </allpages>
  </query>
  <query-continue>
    <allpages apcontinue="DC_Sloník_Humenská_Košice" />
  </query-continue>
</api>