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="20110901143526" timestamp="2011-09-01T14:35:26Z" ns="0" title="Crear un espacio OpenFlyers para su estrúctura" />
        <page value="20120123090211" timestamp="2012-01-23T09:02:11Z" ns="0" title="External wiki links" />
        <page value="20170726133645" timestamp="2017-07-26T13:36:45Z" ns="0" title="Utilización del menù" />
        <page value="20170726140450" timestamp="2017-07-26T14:04:50Z" ns="0" title="Utilización de las tablas" />
        <page value="20170728141957" timestamp="2017-07-28T14:19:57Z" ns="0" title="Bien comunicar con OpenFlyers" />
        <page value="20170728150004" timestamp="2017-07-28T15:00:04Z" ns="0" title="Cuenta cliente OpenFlyers y modelo comercial" />
        <page value="20170728150128" timestamp="2017-07-28T15:01:28Z" ns="0" title="Gestión de las disponibilidades" />
        <page value="20170728150151" timestamp="2017-07-28T15:01:51Z" ns="0" title="Gestión de los usuarios" />
        <page value="20170728150232" timestamp="2017-07-28T15:02:32Z" ns="0" title="Debutar con OpenFlyers" />
        <page value="20170728150314" timestamp="2017-07-28T15:03:14Z" ns="0" title="Configuración de la contabilidad" />
      </results>
    </querypage>
  </query>
</api>