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>
    <querypage name="Ancientpages">
      <results>
        <page value="20060823034702" timestamp="2006-08-23T03:47:02Z" ns="0" title="Source Index" />
        <page value="20060825032708" timestamp="2006-08-25T03:27:08Z" ns="0" title="Source: Marriage certificates" />
        <page value="20060916190528" timestamp="2006-09-16T19:05:28Z" ns="0" title="Source: 1883 History of Butler County Pennsylvania" />
        <page value="20060916191302" timestamp="2006-09-16T19:13:02Z" ns="0" title="Source: Butler and Butler County Pennsylvania 1909" />
        <page value="20060925042944" timestamp="2006-09-25T04:29:44Z" ns="0" title="Tree: Richard Hines, Jr." />
        <page value="20060925220919" timestamp="2006-09-25T22:09:19Z" ns="0" title="Tree: Elizabeth Brandon" />
        <page value="20060925233731" timestamp="2006-09-25T23:37:31Z" ns="0" title="Tree: James Irvin Hogue" />
        <page value="20060925234155" timestamp="2006-09-25T23:41:55Z" ns="0" title="Tree: Elizabeth Hines" />
        <page value="20060930170654" timestamp="2006-09-30T17:06:54Z" ns="0" title="Source: Obituaries" />
        <page value="20060930171159" timestamp="2006-09-30T17:11:59Z" ns="0" title="Source: Birth certificates" />
      </results>
    </querypage>
  </query>
  <query-continue>
    <querypage qpoffset="10" />
  </query-continue>
</api>