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="Fall 2013 Biotechnology and Society" />
          <pl ns="0" title="Fall 2016 Biotechnology and Society" />
          <pl ns="0" title="Hijacking Microbial Factories for Synthetic Biology" />
          <pl ns="0" title="IGEM Wiki" />
          <pl ns="0" title="Spring 2014 Synthetic Biology" />
          <pl ns="0" title="Spring 2015 Microbes as Machines" />
        </links>
      </page>
    </pages>
  </query>
</api>