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>
    <pages>
      <page pageid="1" ns="0" title="Main Page">
        <links>
          <pl ns="0" title="CardGenerator" />
          <pl ns="0" title="Champs Promos" />
          <pl ns="0" title="DCI Legend Membership Poker Deck" />
          <pl ns="0" title="DCI Legend Membership Promos" />
          <pl ns="0" title="Duels of the Planeswalkers" />
          <pl ns="0" title="Duels of the Planeswalkers 2012" />
          <pl ns="0" title="Duels of the Planeswalkers 2013" />
          <pl ns="0" title="Duels of the Planeswalkers 2014" />
          <pl ns="0" title="Duels of the Planeswalkers 2015" />
          <pl ns="0" title="Foreign Promos" />
        </links>
      </page>
    </pages>
  </query>
  <query-continue>
    <links plcontinue="1|0|Forge" />
  </query-continue>
</api>