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="20080302140048" timestamp="2008-03-02T14:00:48Z" ns="0" title="Instalando programas en Lihuen 1" />
        <page value="20080302140715" timestamp="2008-03-02T14:07:15Z" ns="0" title="Trucos" />
        <page value="20080302140728" timestamp="2008-03-02T14:07:28Z" ns="0" title="Solución de Problemas" />
        <page value="20080331132105" timestamp="2008-03-31T13:21:05Z" ns="0" title="Firmware" />
        <page value="20080331132135" timestamp="2008-03-31T13:21:35Z" ns="0" title="Emulando el nuevo Software" />
        <page value="20080501223431" timestamp="2008-05-01T22:34:31Z" ns="0" title="Parsear argumentos en forma elegante con getopt()" />
        <page value="20080502162251" timestamp="2008-05-02T16:22:51Z" ns="0" title="Ejemplo del uso de macros para depurar" />
        <page value="20080502234240" timestamp="2008-05-02T23:42:40Z" ns="0" title="Ejemplo de compilación condicional" />
        <page value="20080507142923" timestamp="2008-05-07T14:29:23Z" ns="0" title="Introducción a la sintaxis dot (graphviz)" />
        <page value="20080507165306" timestamp="2008-05-07T16:53:06Z" ns="0" title="Material de libSDL" />
      </results>
    </querypage>
  </query>
</api>