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>
    <allredirects garcontinue="Cabello_(en_la_Antigüedad_Cristiana)|15021" />
  </query-continue>
  <query>
    <pages>
      <page pageid="937" ns="0" title="Bautizo" />
      <page pageid="2916" ns="0" title="Canonización y Beatificación" />
      <page pageid="7006" ns="0" title="Beelzebul" />
      <page pageid="16924" ns="0" title="Biogenesis y Abiogenesis" />
      <page pageid="17048" ns="0" title="Burchard de Worms" />
      <page pageid="17067" ns="0" title="Enrique de Segusio" />
      <page pageid="17096" ns="0" title="Basilianos" />
      <page pageid="17223" ns="0" title="Alanus de Rupe" />
      <page pageid="17350" ns="0" title="Bardesanes y bardesanitas" />
      <page pageid="17398" ns="0" title="Buena fe" />
    </pages>
  </query>
</api>