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>
    <pages>
      <page pageid="32" ns="0" title="Bestek voor een stalen sleepboot No84" />
      <page pageid="6" ns="0" title="Bolnes" />
      <page pageid="64" ns="0" title="Bolnes Genoten" />
      <page pageid="3" ns="0" title="N.V. Machinefabriek en reparatiebedrijf J.H. Keller Rotterdam" />
      <page pageid="2" ns="0" title="Schipper &amp; Van Dongen" />
      <page pageid="23" ns="0" title="Schless" />
      <page pageid="35" ns="0" title="Willem van Woercom" />
    </pages>
  </query>
</api>