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="20150722034654" timestamp="2015-07-22T03:46:54Z" ns="0" title="Mupen64Plus v2.0 Core Basic" />
        <page value="20150722034718" timestamp="2015-07-22T03:47:18Z" ns="0" title="Mupen64Plus v2.0 Core Debugger" />
        <page value="20150722034815" timestamp="2015-07-22T03:48:15Z" ns="0" title="Mupen64Plus v2.0 Design Proposal 3" />
        <page value="20150722034832" timestamp="2015-07-22T03:48:32Z" ns="0" title="Mupen64Plus v2.0 Plugin API" />
        <page value="20150722034858" timestamp="2015-07-22T03:48:58Z" ns="0" title="Mupen64Plus v2.0 headers" />
        <page value="20150722035839" timestamp="2015-07-22T03:58:39Z" ns="0" title="Main Page" />
        <page value="20150726035403" timestamp="2015-07-26T03:54:03Z" ns="0" title="CodingGuidelines" />
        <page value="20150726041148" timestamp="2015-07-26T04:11:48Z" ns="0" title="CompilingFromHg" />
        <page value="20150726041419" timestamp="2015-07-26T04:14:19Z" ns="0" title="CompilingOnWindows" />
        <page value="20150726054258" timestamp="2015-07-26T05:42:58Z" ns="0" title="ControllerSetup" />
      </results>
    </querypage>
  </query>
</api>