Community Memory 1973 was the first public bulletin board system experiment in Berkeley, California. It aimed to understand how people would exchange information via computer. Online communities have evolved significantly since the 1970s, beginning with Usenet in 1979 and organized into topic-based newsgroups. Multi-user dungeons in the 1980s allowed for text-based virtual worlds. Chat rooms and bulletin board systems hosted on individual systems also emerged. Today, threaded internet forums and social networks facilitate online communities.