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="Bug_Reports" />
  </query-continue>
  <query>
    <allpages>
      <p pageid="405" ns="0" title="Bangla constructions log" />
      <p pageid="2621" ns="0" title="Bangla constructions log page" />
      <p pageid="82" ns="0" title="Bantu Bibliography" />
      <p pageid="2703" ns="0" title="Bare Nominalizations in Norwegian" />
      <p pageid="2300" ns="0" title="Benefactive" />
      <p pageid="1600" ns="0" title="Benefactive SVCs in Mandarin Chinese" />
      <p pageid="1622" ns="0" title="Beneficial" />
      <p pageid="380" ns="0" title="Bengali Constructions" />
      <p pageid="1792" ns="0" title="Brazilian Portuguese" />
      <p pageid="1724" ns="0" title="Brazilian Portuguese (BP)" />
    </allpages>
  </query>
</api>