"Nyx, the world's oldest Internet Service Provider, is a free public-access ISP that free e-mail, (including webmail), web space, web/domain hosting, a full, uncensored Usenet newsfeed, Linux shell accounts and the usual Unix/linux programming and development tools."

It started out on a PDP system at University of Denver in the eighties. https://www.nyx.net/history.html

I used it in the early nineties as a teenager.