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>
    <querypage qpoffset="10" />
  </query-continue>
  <query>
    <querypage name="Ancientpages">
      <results>
        <page value="20060322221948" timestamp="2006-03-22T22:19:48Z" ns="0" title="Microsoft Outlook Express 6" />
        <page value="20060607222356" timestamp="2006-06-07T22:23:56Z" ns="0" title="Reporting Spam Headers - Mozilla Thunderbird" />
        <page value="20060607224925" timestamp="2006-06-07T22:49:25Z" ns="0" title="Reporting Spam Headers - Microsoft Outlook 2003" />
        <page value="20060607224943" timestamp="2006-06-07T22:49:43Z" ns="0" title="Reporting Spam Headers - Microsoft Outlook Express 6" />
        <page value="20060607230738" timestamp="2006-06-07T23:07:38Z" ns="0" title="Reporting Spam Headers - SupraNet Webmail" />
        <page value="20061130215114" timestamp="2006-11-30T21:51:14Z" ns="0" title="Greylisting" />
        <page value="20070104153708" timestamp="2007-01-04T15:37:08Z" ns="0" title="Email Aliases" />
        <page value="20070104153726" timestamp="2007-01-04T15:37:26Z" ns="0" title="Email Groups" />
        <page value="20070104153740" timestamp="2007-01-04T15:37:40Z" ns="0" title="Email Failed Addresses" />
        <page value="20080403180225" timestamp="2008-04-03T18:02:25Z" ns="0" title="Apple Mail Setup In Mac OS X 10.5" />
      </results>
    </querypage>
  </query>
</api>