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="Publicacions" />
  </query-continue>
  <query>
    <pages>
      <page ns="0" title="Gerontologia" missing="" />
      <page ns="0" title="Psicologia infantil" missing="" />
      <page pageid="30" ns="0" title="Com ho fem" />
      <page pageid="28" ns="0" title="Como lo hacemos" />
      <page pageid="7" ns="0" title="Curriculum" />
      <page pageid="43" ns="0" title="Deficiencia mental" />
      <page pageid="54" ns="0" title="Desenvolupament" />
      <page pageid="31" ns="0" title="Infancia" />
      <page pageid="18" ns="0" title="Mapa" />
      <page pageid="33" ns="0" title="Protocols" />
    </pages>
  </query>
</api>