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>
    <revisions rvcontinue="3348" />
  </query-continue>
  <query>
    <pages>
      <page pageid="206993" ns="0" title="Main Page">
        <revisions>
          <rev user="Rob Linden" timestamp="2006-12-04T22:07:42Z" comment="" />
          <rev user="Rob Linden" timestamp="2006-12-05T00:32:59Z" comment="[[Main Page]] moved to [[Open Source Portal]]: Will be creating a new [[Main Page]], current prototype is at [[New Main Page]] (which is too sparse to use just yet)" />
          <rev user="Rob Linden" timestamp="2006-12-15T06:08:55Z" comment="" />
          <rev user="Rob Linden" timestamp="2006-12-29T08:49:07Z" comment="" />
          <rev user="Rob Linden" timestamp="2006-12-29T08:49:31Z" comment="[[New Main Page]] moved to [[Main Page]]: No time like the present" />
        </revisions>
      </page>
    </pages>
  </query>
</api>