INN also stands for InterNetNews, an NNTP (Usenet news) server software, brought to you by ISC and Rich Saltz.
INN is one of the most widely used news servers - and it's intended for news serving on big, public news servers, at ISP level or higher. One of the features for this use is that it can receive a newsfeed and pass stuff to downstream news servers.
It's probably as good news daemon as you can get, but probably overkill if you're running a dialup site with only a couple of users and with only one point to outside world - LeafNode is probably what you'd want in that case.