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>
    <recentchanges rccontinue="20161004012019|7459" />
  </query-continue>
  <query>
    <recentchanges>
      <rc type="edit" ns="0" title="Página principal" pageid="678" revid="7399" old_revid="7398" rcid="7469" timestamp="2017-12-12T17:34:05Z" />
      <rc type="edit" ns="0" title="Página principal" pageid="678" revid="7398" old_revid="6514" rcid="7468" timestamp="2017-12-12T17:33:26Z" />
      <rc type="edit" ns="0" title="Latex" pageid="1105" revid="7397" old_revid="7203" rcid="7467" timestamp="2017-03-03T18:48:49Z" />
      <rc type="edit" ns="0" title="Tareas de Lihuen" pageid="498" revid="7396" old_revid="3102" rcid="7466" timestamp="2016-10-04T01:29:56Z" />
      <rc type="edit" ns="0" title="Clientes livianos con LTSP5" pageid="503" revid="7395" old_revid="3885" rcid="7465" timestamp="2016-10-04T01:24:25Z" />
      <rc type="edit" ns="0" title="Instalación de Ltspconfig" pageid="502" revid="7394" old_revid="3345" rcid="7464" timestamp="2016-10-04T01:23:55Z" />
      <rc type="edit" ns="0" title="Ltspconfig" pageid="440" revid="7393" old_revid="3374" rcid="7463" timestamp="2016-10-04T01:23:26Z" />
      <rc type="edit" ns="0" title="Instalando y configurando bootsplash" pageid="242" revid="7392" old_revid="2911" rcid="7462" timestamp="2016-10-04T01:22:14Z" />
      <rc type="edit" ns="0" title="How to Live-cd Lihuen" pageid="219" revid="7391" old_revid="2887" rcid="7461" timestamp="2016-10-04T01:21:33Z" />
      <rc type="edit" ns="0" title="Instalando chromium-browser" pageid="563" revid="7390" old_revid="5158" rcid="7460" timestamp="2016-10-04T01:20:55Z" />
    </recentchanges>
  </query>
</api>