You are looking at the HTML representation of the XML format.
HTML is good for debugging, but probably is not suitable for your application.
See complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query>
    <pages>
      <page pageid="1" ns="0" title="Main Page">
        <revisions>
          <rev user="Cedwards" timestamp="2007-05-07T20:56:56Z" comment="" />
          <rev user="Junk Skynrd" timestamp="2007-05-15T07:11:48Z" comment="" />
          <rev user="Cedwards" timestamp="2007-05-15T07:16:49Z" comment="" />
          <rev user="Cedwards" timestamp="2007-06-25T18:37:13Z" comment="Protected &quot;[[Main Page]]&quot; [edit=sysop:move=sysop] [cascading]" />
          <rev user="Chk" timestamp="2010-02-23T22:42:41Z" comment="" />
        </revisions>
      </page>
    </pages>
  </query>
  <query-continue>
    <revisions rvstartid="8078" />
  </query-continue>
</api>