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="Classes_sociales|936" />
  </query-continue>
  <query>
    <pages>
      <page pageid="427" ns="12" title="Aide:Groupe MPAPA (Démarrage)" />
      <page pageid="457" ns="106" title="MP:Journal de création Dominique" />
      <page pageid="475" ns="106" title="MP:Le je à l&#039;œuvre" />
      <page pageid="478" ns="106" title="MP:Réunions cahier" />
      <page pageid="498" ns="106" title="MP:Cahier Le Je à l&#039;œuvre" />
      <page pageid="499" ns="0" title="Journal de création" />
      <page pageid="501" ns="106" title="MP:Ordre du jour des réunions MPAPA" />
      <page pageid="900" ns="0" title="Le Je au travail" />
      <page pageid="930" ns="10" title="Modèle:SommaireImage" />
      <page pageid="931" ns="0" title="Image" />
    </pages>
  </query>
</api>