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>
    <allfileusages gafcontinue="Interfaces.jpg|1" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1" ns="0" title="Página principal" />
      <page pageid="19" ns="0" title="Erro ao abrir o MG-Soft Web" />
      <page pageid="26" ns="0" title="Erro de timeout ao abrir o software" />
      <page pageid="54" ns="0" title="Como importar agenda de apartamentos" />
      <page pageid="85" ns="0" title="Confecção do cabo serial" />
      <page pageid="154" ns="0" title="Como saber o número de série do equipamento" />
      <page pageid="157" ns="0" title="Imagem placa Bravo" />
    </pages>
  </query>
</api>