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="Collapsible_option|21" />
  </query-continue>
  <query>
    <pages>
      <page pageid="34" ns="10" title="Template:Cite episode" />
      <page pageid="35" ns="10" title="Template:Cite interview" />
      <page pageid="54" ns="10" title="Template:Dead link" />
      <page pageid="56" ns="10" title="Template:Fix" />
      <page pageid="63" ns="10" title="Template:Good article" />
      <page pageid="75" ns="10" title="Template:Infobox person" />
      <page pageid="76" ns="10" title="Template:Lang" />
      <page pageid="148" ns="10" title="Template:Infobox person/doc" />
      <page pageid="226" ns="10" title="Template:Infobox/doc" />
    </pages>
  </query>
</api>