They carry a very small number of podcasts, the whole listing fits onto two pages.
One requests to be added to the site using a form on the site. They apparently review and approve listings. The listings that are there are marked with links to "Claim your blog" as if the listings on the site were added without the podcasters making a request. I suspect this is a new site that's still in development.
The listings are simply links, there's no aggregation etc.