Most public forums back in the day would have been vastly improved if they had been done as an NNTP server with each sub-forum as a newsgroup rather than doing them with something like phpBBB on an HTTP server.
Heck, most forums today would have better threading and post organization with NNTP than they do with the popular web forum systems.
Same goes for non-chat communication within companies. Newsgroups on an internal NNTP server would be better in most ways than mailing lists for topics in which people actually need to discuss things as a group.