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="BayArena|58" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1" ns="0" title="Hauptseite" />
      <page pageid="7" ns="0" title="Stadionkomplex" />
      <page pageid="15" ns="0" title="Das Rheinderby gegen den FC Köln" />
      <page pageid="34" ns="0" title="Christoph Daum" />
      <page pageid="35" ns="0" title="Michael Ballack" />
      <page pageid="40" ns="0" title="Nordkurve12" />
      <page pageid="79" ns="0" title="Bayer AG" />
      <page pageid="99" ns="0" title="Marek Lesniak" />
      <page pageid="102" ns="0" title="Rudi Völler" />
    </pages>
  </query>
</api>