Usenet is a worldwide, distributed discussion system organized into thematic newsgroups, created in 1980 by graduate students Tom Truscott and Jim Ellis to link university computers over dial-up. Unlike a centralized forum, Usenet has no single server: articles are flooded from host to host, so a message posted on one machine eventually propagates across the whole network. It was one of the first large-scale online communities and, for two decades, the main public square of the internet’s technical population.
The format of those articles was standardized so that independently written software could interoperate. RFC 850, and its later revision RFC 1036 (“Standard for Interchange of USENET Messages”), specify the structure of a news article. RFC 1036 states that “all USENET news messages must be formatted as valid Internet mail messages,” reusing the RFC 822 mail format and defining required headers such as From, Date, Newsgroups, Subject, Message-ID, and Path. The Path and Message-ID headers are central to propagation: they let each host avoid sending an article back to a machine that has already seen it, preventing infinite loops as messages spread.
Articles are carried between servers by the Network News Transfer Protocol, NNTP, which lets a client read and post and lets servers exchange batches of new articles efficiently. The newsgroups themselves are arranged in a hierarchy, with top-level categories like comp for computing, sci for science, and the freewheeling alt for everything else, so that the namespace itself encodes the structure of the conversation.
Usenet’s history includes a famous act of housekeeping known as the Great Renaming, carried out in the mid-1980s, which reorganized the sprawling newsgroup hierarchy into the cleaner top-level categories that followed. The reorganization was contentious, and the parallel creation of the unmoderated alt hierarchy was in part a reaction against centralized control over what groups could exist.
Two phrases from Usenet entered the broader culture of the net. Flame wars, the long hostile arguments that erupted in threads, became a defining hazard of unmoderated discussion. And the “September that never ended” named the moment in 1993 when a major commercial provider gave its subscribers Usenet access year-round; the annual September influx of clueless newcomers, which old hands had always endured for a few weeks, now simply never stopped. Both ideas became durable shorthand for the social dynamics of any large online community.