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="CSS|1423" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1371" ns="0" title="Site Map" />
      <page pageid="1373" ns="0" title="Social Media" />
      <page pageid="1375" ns="0" title="Microblogging" />
      <page pageid="1391" ns="0" title="Internet" />
      <page pageid="1397" ns="0" title="Social media" />
      <page pageid="1407" ns="0" title="Articles to write" />
      <page pageid="1408" ns="0" title="How to make a website" />
      <page pageid="1423" ns="0" title="Developer-hosted platform" />
      <page pageid="1429" ns="0" title="Internet hosting service" />
    </pages>
  </query>
</api>