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>
    <allredirects garcontinue="Course_syllabus_suggestions" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1548" ns="0" title="Ball and Beam Introduction" />
      <page pageid="1337" ns="0" title="Ball and beam system" />
      <page pageid="1317" ns="0" title="Bibliography" />
      <page pageid="2331" ns="0" title="Biomolecular Feedback Systems" />
      <page pageid="1498" ns="0" title="Chapter 2 - System Modeling" />
      <page pageid="1445" ns="0" title="Chapter 4 - Dynamic Behavior" />
      <page pageid="1500" ns="0" title="Chapter 5 - Linear Systems" />
      <page pageid="1502" ns="0" title="Chapter 6 - State Feedback" />
      <page pageid="1504" ns="0" title="Chapter 7 - Output Feedback" />
      <page pageid="1537" ns="0" title="Citation information" />
    </pages>
  </query>
</api>