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>
    <allredirects garcontinue="La_Gaignonnière|5" />
  </query-continue>
  <query>
    <pages>
      <page pageid="3" ns="0" title="La Gaignonniere" />
      <page pageid="4" ns="0" title="La Gagnonniere" />
      <page pageid="7" ns="0" title="Barnabe Gaignon" />
      <page pageid="8" ns="0" title="Barnabé Gaignon" />
      <page pageid="9" ns="0" title="Barnabe Gagnon" />
      <page pageid="54" ns="0" title="Elie Gagnon" />
      <page pageid="71" ns="0" title="Charles Gagnon" />
      <page pageid="92" ns="0" title="Barnabé Gagnon" />
      <page pageid="128" ns="0" title="Marie Cecile Rosa Gagnon" />
      <page pageid="129" ns="0" title="Marie Blanche Alice Gagnon" />
    </pages>
  </query>
</api>