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>
    <alllinks>
      <l ns="0" title="Basic equipment" />
      <l ns="0" title="Benutzernamen registrieren" />
      <l ns="0" title="Blank Text Permanent" />
      <l ns="0" title="Boost creature type" />
      <l ns="0" title="COMMUNITY DLC Tutorial - Setup Tortoise SVN" />
      <l ns="0" title="Can be played as sorcery" />
      <l ns="0" title="CardGenerator" />
      <l ns="0" title="Challenge Mode" />
      <l ns="0" title="Champs Promos" />
      <l ns="0" title="Champs Promos (2006)" />
    </alllinks>
  </query>
  <query-continue>
    <alllinks alcontinue="Champs_Promos_(2007)" />
  </query-continue>
</api>