A private, non-federated NNTP server that hosts newsgroups. Apply for an account, configure a news client, enjoy.
Eternal September is a free online Usenet feed for people who still feel the need to read net.news. You can only access text newsgroups (i.e. no alt.binary.*) and you have to register an account, but other than that it's open season. They also support UUCP if you roll that way.
FOSS software which implements a mailing list, not just over email but as a sharable, clonable git repo. Implements nntp, online html archives, and atom feeds. Written in perl. Designed to run on the lower possible common denominator machine. Uses a pull model, which optimizes for casual readers and members while still allowing for serious users.
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