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="Ceska_Kamenice_DC_CZ.png|33" />
  </query-continue>
  <query>
    <pages>
      <page pageid="32" ns="0" title="Město Benešov nad Ploučnicí" />
      <page pageid="47" ns="0" title="Obec Bynovec" />
      <page pageid="81" ns="0" title="Belveder" />
      <page pageid="116" ns="0" title="Billa Děčín Plzeňská" />
      <page pageid="117" ns="0" title="Billa Děčín Řetězová" />
      <page pageid="161" ns="0" title="ČSOB Děčín Řetězová" />
      <page pageid="774" ns="0" title="Buk lesní" />
      <page pageid="1024" ns="0" title="Betonárna Cemex Děčín" />
    </pages>
  </query>
</api>