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="Chumby_Service_Settings_in_/psp" />
  </query-continue>
  <query>
    <allpages>
      <p pageid="1429" ns="0" title="Bag filter" />
      <p pageid="1388" ns="0" title="Bartender Widget" />
      <p pageid="1312" ns="0" title="Blinging for chumby" />
      <p pageid="1381" ns="0" title="Btplay.current" />
      <p pageid="1459" ns="0" title="Building OpenEmbedded (Beta)" />
      <p pageid="1392" ns="0" title="ChumbyNative" />
      <p pageid="1397" ns="0" title="Chumby Flash Tutorials" />
      <p pageid="1419" ns="0" title="Chumby One tips and tricks" />
      <p pageid="1376" ns="0" title="Chumby Property Dictionary" />
      <p pageid="1426" ns="0" title="Chumby Rootdisk - RFS1 (analyzed)" />
    </allpages>
  </query>
</api>