Users' group

A users' group (also user's group or user group) is a type of club focused on the use of a particular technology, usually (but not always) computer-related.

Users' groups started in the early days of mainframe computers, as a way to share sometimes hard-won knowledge and useful software, usually written by end users independently of the vendor-supplied programming efforts. SHARE, a user group originated by aerospace industry corporate users of IBM mainframe computers, was founded in 1955 and is the oldest computer user group still active. DECUS, the DEC User's Society, was founded in 1961 and its descendant organization, Connect Worldwide, still operates. The Computer Measurement Group (CMG) was founded in 1974 by systems professionals with a common interest in (mainframe) capacity management, and continues today with a much broader mission. The first UNIX users' group organized in 1978.