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>
    <alllinks galcontinue="Hlášené_poruchy|2" />
  </query-continue>
  <query>
    <pages>
      <page pageid="2" ns="0" title="Seznam zařízení GCOM" />
      <page pageid="23" ns="0" title="Nejčastější dotazy" />
      <page pageid="40" ns="0" title="Harmonogram provozu" />
      <page pageid="69" ns="0" title="Denní report" />
      <page pageid="76" ns="0" title="Poslední data" />
      <page pageid="83" ns="0" title="Sumační data" />
      <page pageid="137" ns="0" title="Denní report - graf" />
    </pages>
  </query>
</api>