How'd they do that? Here's the secret:
<?xml-stylesheet type="text/xsl" href="rss_stylesheet.xsl"?>
Yep. All of the HTML fluff is statically defined in a stylesheet, comon to half a dozen news feeds. Aggregators are happy, and reasonable browsers do something useful. Feeds change, and there's no work to be done. Change the shell once, and it's used for all six feeds.
And that's the way it should be.