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="Database_corruption" />
  </query-continue>
  <query>
    <allpages>
      <p pageid="1428" ns="0" title="Bitmap Failed internal checks" />
      <p pageid="1374" ns="0" title="Brainbench DBA certification" />
      <p pageid="1297" ns="0" title="Bulk copy out of text and image data" />
      <p pageid="1418" ns="0" title="Bypasssing cross platform load issues" />
      <p pageid="1321" ns="0" title="Capturing IQ query plans" />
      <p pageid="1292" ns="0" title="Configuration Settings" />
      <p pageid="1406" ns="0" title="Corruption of Syslogs (log suicide)" />
      <p pageid="1407" ns="0" title="Corruption of syslogs" />
      <p pageid="1350" ns="0" title="Corruption of syslogs (dbcc rebuild log)" />
      <p pageid="1423" ns="0" title="Could not find or load the physical store DLL" />
    </allpages>
  </query>
</api>