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="Delete|752" />
  </query-continue>
  <query>
    <pages>
      <page pageid="728" ns="0" title="Knoppix Customizations" />
      <page pageid="736" ns="0" title="Knoppix FAQ" />
      <page pageid="737" ns="0" title="General FAQ" />
      <page pageid="744" ns="0" title="Cheat Codes Deutsch" />
      <page pageid="745" ns="0" title="Knoppix Installer" />
      <page pageid="747" ns="0" title="Basic Poor Mans" />
      <page pageid="750" ns="0" title="Pivot Root Install" />
      <page pageid="751" ns="0" title="Hd Install HowTo" />
      <page pageid="1674" ns="0" title="Installation of older Knopix to HDD" />
      <page pageid="1775" ns="0" title="Knoppix Remastering Howto Portuguese-Brazilian" />
    </pages>
  </query>
</api>