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="BauO_NRW|25" />
  </query-continue>
  <query>
    <pages>
      <page pageid="25" ns="0" title="Bauordnungen und Sonderbauordnungen" />
      <page pageid="28" ns="0" title="DIN- und EN-Normen" />
      <page pageid="162" ns="0" title="MLAR" />
      <page pageid="168" ns="0" title="Verantwortung für den Brandschutz" />
      <page pageid="185" ns="0" title="Brandmelderzentralen DIN EN 54-2" />
      <page pageid="318" ns="0" title="Sprachalarm VDE 0833-4 Produkte" />
      <page pageid="463" ns="2" title="Benutzer:Beplan" />
    </pages>
  </query>
</api>