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 alcontinue="CSA_La_Revolucioná|29" />
  </query-continue>
  <query>
    <alllinks>
      <l ns="0" title="BASES DE DATOS" />
      <l ns="0" title="BORRADOR ENCUESTA" />
      <l ns="0" title="Bahía" />
      <l ns="0" title="Base de datos nuevos equipamientos barriales" />
      <l ns="0" title="Biblioteca Social Hermano Quero" />
      <l ns="0" title="Biblioteca Social libre Albedrío" />
      <l ns="0" title="Bola de Oro" />
      <l ns="0" title="CSA El lokal" />
      <l ns="0" title="CSA En pie" />
      <l ns="0" title="CSA La Fábrika" />
    </alllinks>
  </query>
</api>