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>
    <alltransclusions gatcontinue="BasicAdmin_Navbar" />
  </query-continue>
  <query>
    <pages>
      <page pageid="15103" ns="10" title="Template:BIF About" />
      <page pageid="15116" ns="10" title="Template:BIF About/NO" />
      <page pageid="14747" ns="10" title="Template:BIF Collaboration" />
      <page pageid="14776" ns="10" title="Template:BIF Collaboration Summary" />
      <page pageid="15106" ns="10" title="Template:BIF Navbar" />
      <page pageid="15120" ns="10" title="Template:BIF Projects" />
      <page pageid="18141" ns="10" title="Template:BIF Slideshow" />
      <page pageid="15234" ns="10" title="Template:BIF Visjon2030" />
      <page pageid="15316" ns="10" title="Template:BIF Visjon2030/NO" />
      <page pageid="14640" ns="10" title="Template:BN TOC" />
    </pages>
  </query>
</api>