Before chatrooms and blogs, before instant messengers, text messages, and mobile phones, and even before the World Wide Web itself, there was “Usenet”. Devised at Duke University in 1979, and launched in 1980 (making it one of the oldest computer networks still in widespread use), Usenet was a system designed as a replacement for a local announcement program. As more and more servers were added to the network, however, Usenet quickly became a large online community allowing people to post messages to online bulletin boards on a wide variety of subjects.
Usenet is organised into a hierarchy of topical categories, known as “newsgroups”. Each is then organised into hierarchies of subjects. For instance, “sci.math” and “sci.physics” are in the “sci” category. Each category can be further subdivided, leading to, for example, newsgroups with names such as “misc.uk.politics”. There are nine principal top-level categories: comp.*, humanties.*, misc.*, news.*, rec.*, sci.*, soc.*, talk.* and alt.*.
Culturally, Usenet has been of great significance to the networked world. Contributions to language (or popularisations of existing terms) include as “FAQ”, “spam”, “netiquette”, “trolling” and “flamewar”, but perhaps the most important cultural contribution has been the introduction and acceptance of the idea of a shared, decentralised online community. Today “peer-to-peer” networks are much in the news, used in applications from sharing of music, to illegal file-sharing, to Skype, and even the search for cures for cancer or extra-terrestrial intelligence, but the first large and decentralised online community was Usenet.
While still accessible through traditional, standalone “newsreader” software, Usenet is today also accessible through web gateways. One example is Google Groups, which maintains a searchable archive of Usenet posts going back to 1981 (here's how to use Groups for that). Historically, Usenet has seen the first announcements of some of the most far-reaching changes to modern life; Usenet, for example, was the place where Tim Berners-Lee announced the launch of the World Wide Web; it was where Linus Torvalds announced the Linux project; and it was where Marc Andreessen announced the Mosaic web browser - and the accompanying code to allow images to be displayed in a web browser for the first time, revolutionising the web by turning it into a graphical medium.
Tell that to kids these days, and they'll never believe you.