By default the mod hub is located at this gamespy address, which is a web service, so not browseable using just a browser. Is there a service available somewhere that will allow me to browse the mods directory, preferably with sorting capabilities?
Well, I guess you already know this but you can use a SOAP client to view the data.. for example: http://stackoverflow.com/questions/206154/whats-the-best-soap-client-library-for-python-and-where-is-the-documentation-fo
You will now see all the categories..
Now just for someone to implement it in a webapplication :)
As of version 18.104.22.1684, mods are now published on the Steam Workshop for Civilization V, which is available for browsing outside the game.