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="20090707131444" timestamp="2009-07-07T13:14:44Z" ns="0" title="GEOS-Chem Newsletter February 2009" />
        <page value="20090707134854" timestamp="2009-07-07T13:48:54Z" ns="0" title="Additional diagnostics" />
        <page value="20100211151405" timestamp="2010-02-11T15:14:05Z" ns="0" title="GEOS-Chem Newsletter January 2009" />
        <page value="20100428193030" timestamp="2010-04-28T19:30:30Z" ns="0" title="GEOS-Chem Newsletter April 2010" />
        <page value="20110328162555" timestamp="2011-03-28T16:25:55Z" ns="0" title="GEOS-Chem Newsletter March 2011" />
        <page value="20120107004049" timestamp="2012-01-07T00:40:49Z" ns="0" title="GEOS-Chem Adjoint v31" />
        <page value="20130703230625" timestamp="2013-07-03T23:06:25Z" ns="0" title="GEOS-Chem Adjoint v33" />
        <page value="20130703230740" timestamp="2013-07-03T23:07:40Z" ns="0" title="GEOS-Chem Adjoint v32" />
        <page value="20130724212733" timestamp="2013-07-24T21:27:33Z" ns="0" title="GEOS-Chem Adjoint v34" />
        <page value="20130914014954" timestamp="2013-09-14T01:49:54Z" ns="0" title="Process Analysis Diagnostics" />
      </results>
    </querypage>
  </query>
</api>