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="Créditos_2010" />
  </query-continue>
  <query>
    <pages>
      <page ns="0" title="Civilization" missing="" />
      <page pageid="107" ns="0" title="Bagh Chal" />
      <page pageid="238" ns="0" title="Battle for Olympus" />
      <page pageid="2" ns="0" title="Carcassonne" />
      <page pageid="282" ns="0" title="Caylus" />
      <page pageid="44" ns="0" title="Ciudadelas" />
      <page pageid="76" ns="0" title="Colonos de Catan" />
      <page pageid="23" ns="0" title="Colonos de Catán" />
      <page pageid="9" ns="0" title="Corintho" />
      <page pageid="221" ns="0" title="Corporation" />
    </pages>
  </query>
</api>