Every Podcast is a podcast directory that looks to be badly implemented.
The podcasts have "tags" associated with each, the tags act as the categorization. While this should make for a better classification system than a fixed hierarchy of topics the implementation here leaves something to be desired. First you only see the most popular tags, so if it's an unpopular tag you're looking for it's going to be difficult to find. Second, as is usual for tag displays, you end up with a bunch of words crammed together as the navigational scheme. Hmm..
Anybody can add a podcast. The tagging is probably generated automatically, since when you add a podcast all you do is specify the URL.