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>
    <querypage name="Ancientpages">
      <results>
        <page value="20130830160345" timestamp="2013-08-30T16:03:45Z" ns="0" title="Main Page" />
        <page value="20130831024844" timestamp="2013-08-31T02:48:44Z" ns="0" title="Criando um Banco de Dados" />
        <page value="20130903133400" timestamp="2013-09-03T13:34:00Z" ns="0" title="Criando contas de e-mail" />
        <page value="20130903133532" timestamp="2013-09-03T13:35:32Z" ns="0" title="Como acessar meus e-mails?" />
        <page value="20130903142648" timestamp="2013-09-03T14:26:48Z" ns="0" title="Microsoft Outlook 2013" />
        <page value="20130903184347" timestamp="2013-09-03T18:43:47Z" ns="0" title="Como enviar meus arquivos pelo cPanel?" />
        <page value="20130903184658" timestamp="2013-09-03T18:46:58Z" ns="0" title="Página principal" />
        <page value="20130903184953" timestamp="2013-09-03T18:49:53Z" ns="0" title="Onde coloco os meus arquivos?" />
      </results>
    </querypage>
  </query>
</api>