You are looking at the HTML representation of the mFormat?> format.
HTML is good for debugging, but probably is not suitable for your application.
Please see "format" parameter documentation at the API help for more information.
<?xml version="1.0" encoding="utf-8"?>
<api>
  <query>
    <pages>
      <page pageid="1" ns="0" title="Main Page" />
    </pages>
    <backlinks />
  </query>
</api>