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>
    <allpages apcontinue="Believed_behavior" />
  </query-continue>
  <query>
    <allpages>
      <p pageid="29" ns="0" title="BERG Publishers" />
      <p pageid="331" ns="0" title="Backspace Generation" />
      <p pageid="966" ns="0" title="Balanced Reciprocity" />
      <p pageid="1027" ns="0" title="Banff New Media Institute" />
      <p pageid="1028" ns="0" title="Banff Summit on Living Architectures: Designing for Immersion and Interaction" />
      <p pageid="195" ns="0" title="Bedtime for Bonzo" />
      <p pageid="413" ns="0" title="Bee Dance" />
      <p pageid="88" ns="0" title="Behavior in Public Places" />
      <p pageid="1081" ns="0" title="Behavior in Public Places: Notes on the Social Organization of Gatherings" />
      <p pageid="126" ns="0" title="Being Digital" />
    </allpages>
  </query>
</api>