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>
    <allfileusages gafcontinue="Figure_2.3.jpg|4" />
  </query-continue>
  <query>
    <pages>
      <page pageid="3" ns="0" title="Symbian OS Platform Security/01. Why a Secure Platform?" />
      <page pageid="4" ns="0" title="Symbian OS Platform Security/02. Platform Security Concepts" />
      <page pageid="12" ns="0" title="Symbian OS Platform Security/10. The Servant in Your Pocket" />
      <page pageid="64" ns="0" title="License" />
      <page pageid="165" ns="0" title="Enigma/Simulator User Guide" />
      <page pageid="268" ns="0" title="HW 25/22" />
    </pages>
  </query>
</api>