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>
    <allpages apcontinue="Dev200-intranet.php" />
  </query-continue>
  <query>
    <allpages>
      <p pageid="481" ns="0" title="Cahier Le Je à l&#039;œuvre" />
      <p pageid="480" ns="0" title="Comptes rendus 2014 MPAPA" />
      <p pageid="479" ns="0" title="Comptes rendus 2015 MPAPA" />
      <p pageid="584" ns="0" title="Comptes rendus MPAPA" />
      <p pageid="952" ns="0" title="Comptes rendus des réunions MPAPA" />
      <p pageid="951" ns="0" title="Comptes rendus du groupe lecture" />
      <p pageid="135" ns="0" title="Dev-200-pannePartielle.html" />
      <p pageid="161" ns="0" title="Dev-200-sqlsi.infoChercheurs" />
      <p pageid="382" ns="0" title="Dev200-accueilAboLettre.php" />
      <p pageid="208" ns="0" title="Dev200-intradhesions.php" />
    </allpages>
  </query>
</api>