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="Blue|3564" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1951" ns="0" title="End Summer Camp 2012" />
      <page pageid="3011" ns="10" title="Template:ESC12-Destra" />
      <page pageid="3435" ns="0" title="End Summer Camp 2013" />
      <page pageid="3444" ns="10" title="Template:ESC13-Destra" />
      <page pageid="3458" ns="0" title="End Summer Camp 2014" />
      <page pageid="3460" ns="10" title="Template:ESC14-Destra" />
      <page pageid="3497" ns="10" title="Template:ESC15-Destra" />
      <page pageid="3521" ns="0" title="End Summer Camp 2015" />
      <page pageid="3552" ns="10" title="Template:ESC16-Destra" />
      <page pageid="3561" ns="0" title="End Summer Camp 2017" />
    </pages>
  </query>
</api>