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"?>
    <allpages apcontinue="Branding,_the_next_level" />
      <p pageid="1280" ns="0" title="Backups" />
      <p pageid="2581" ns="0" title="Bazaar Bounties" />
      <p pageid="2661" ns="0" title="Bazaar Edinburgh 2012" />
      <p pageid="2591" ns="0" title="Bazaar Glasgow 2011" />
      <p pageid="2560" ns="0" title="Bazaar Southampton 2010" />
      <p pageid="1946" ns="0" title="BibTeX Extension Example" />
      <p pageid="1642" ns="0" title="Bin/" />
      <p pageid="1966" ns="0" title="Bin/export" />
      <p pageid="1882" ns="0" title="Boolean field" />
      <p pageid="2572" ns="0" title="Boxes on Abstract Pages" />