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="20130529142916" timestamp="2013-05-29T14:29:16Z" ns="0" title="Main Page" />
        <page value="20130529143003" timestamp="2013-05-29T14:30:03Z" ns="0" title="Differences" />
        <page value="20130529143014" timestamp="2013-05-29T14:30:14Z" ns="0" title="Warcraft 3 Frozen Throne:Plugin Information" />
        <page value="20130529143028" timestamp="2013-05-29T14:30:28Z" ns="0" title="Warcraft 3 Frozen Throne:Plugin Information French" />
        <page value="20130529143036" timestamp="2013-05-29T14:30:36Z" ns="0" title="Warcraft 3 Frozen Throne:Plugin Information Russian" />
        <page value="20130529143119" timestamp="2013-05-29T14:31:19Z" ns="0" title="Warcraft 3 Expansion:Configuration" />
        <page value="20130529143149" timestamp="2013-05-29T14:31:49Z" ns="0" title="Warcraft 3 Frozen Throne:New Installation" />
        <page value="20130529143244" timestamp="2013-05-29T14:32:44Z" ns="0" title="Warcraft 3 Frozen Throne:Upgrading" />
        <page value="20130529143302" timestamp="2013-05-29T14:33:02Z" ns="0" title="Warcraft 3 Frozen Throne:Frequently Asked Questions" />
        <page value="20130529143317" timestamp="2013-05-29T14:33:17Z" ns="0" title="Warcraft 3 Frozen Throne:How Tos" />
      </results>
    </querypage>
  </query>
</api>