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="Bec_Bunsen" />
  </query-continue>
  <query>
    <pages>
      <page ns="0" title="Bain-marie" missing="" />
      <page ns="0" title="Bain de glace/sel" missing="" />
      <page ns="0" title="Baryum" missing="" />
      <page pageid="2194" ns="0" title="Balance de précision" />
      <page pageid="156" ns="0" title="Balle rebondissante" />
      <page pageid="2206" ns="0" title="Ballon" />
      <page pageid="2189" ns="0" title="Ballon bicol" />
      <page pageid="2397" ns="0" title="Ballon réduit et auto-gonflé" />
      <page pageid="2313" ns="0" title="Ballon tricol" />
      <page pageid="2204" ns="0" title="Barreau aimanté" />
    </pages>
  </query>
</api>