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="Configuration_Accounting3|2118" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1997" ns="0" title="Comptabilité" />
      <page pageid="2008" ns="0" title="FAQ client" />
      <page pageid="2011" ns="0" title="FAQ utilisateur" />
      <page pageid="2090" ns="0" title="Écritures comptables" />
      <page pageid="2160" ns="0" title="Conseils spécifiques pour la comptabilité" />
      <page pageid="2163" ns="0" title="Historique des versions d&#039;OpenFlyers" />
      <page pageid="2218" ns="0" title="Bien communiquer avec OpenFlyers" />
      <page pageid="2511" ns="0" title="Accueil" />
      <page pageid="2576" ns="0" title="Import dans un logiciel comptable tiers" />
    </pages>
  </query>
</api>