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="Ball_and_beam_system|1710" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1" ns="0" title="First Edition" />
      <page pageid="1329" ns="0" title="Exercise: Exploring the dynamics of the ball and beam system" />
      <page pageid="1342" ns="0" title="Applications and Examples" />
      <page pageid="1346" ns="0" title="System Modeling" />
      <page pageid="1442" ns="0" title="Additional Examples" />
      <page pageid="1524" ns="0" title="Introduction/Homework/Ball and Beam" />
      <page pageid="1668" ns="0" title="Supplement: Biomolecular Feedback Systems" />
      <page pageid="1675" ns="0" title="Archived news" />
      <page pageid="1783" ns="0" title="FAQ: How are stability, performance and robustness different?" />
    </pages>
  </query>
</api>