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="4" ns="0" title="Configurations" />
      <page pageid="7" ns="0" title="Dynamically splitting output into files while processing" />
      <page pageid="3" ns="0" title="Installations" />
      <page pageid="5" ns="0" title="Other" />
      <page pageid="10" ns="0" title="Plotting schools Port Elizabeth using shell scripting" />
      <page pageid="9" ns="0" title="Retrieving Flickr photo views using shell scripting" />
      <page pageid="6" ns="0" title="Scripting" />
    </pages>
  </query>
</api>