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>
    <allpages>
      <p pageid="4" ns="0" title="Configurations" />
      <p pageid="8" ns="0" title="Dynamic splitting output into files while processing" />
      <p pageid="7" ns="0" title="Dynamically splitting output into files while processing" />
      <p pageid="3" ns="0" title="Installations" />
      <p pageid="1" ns="0" title="Main Page" />
      <p pageid="5" ns="0" title="Other" />
      <p pageid="10" ns="0" title="Plotting schools Port Elizabeth using shell scripting" />
      <p pageid="9" ns="0" title="Retrieving Flickr photo views using shell scripting" />
      <p pageid="6" ns="0" title="Scripting" />
    </allpages>
  </query>
</api>