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>
    <alllinks galcontinue="Crítica" />
  </query-continue>
  <query>
    <pages>
      <page ns="0" title="Caras y Caretas" missing="" />
      <page ns="0" title="Clarín" missing="" />
      <page pageid="105" ns="0" title="Candilejas (década de 1950)" />
      <page pageid="106" ns="0" title="Candilejas (década de 1980)" />
      <page pageid="13" ns="0" title="Cine 64" />
      <page pageid="19" ns="0" title="Cine prensa" />
      <page pageid="115" ns="0" title="Cine revista (1)" />
      <page pageid="114" ns="0" title="Cine revista (década de 1930)" />
      <page pageid="107" ns="0" title="Cine y medios" />
      <page pageid="63" ns="0" title="Cineset" />
    </pages>
  </query>
</api>