Some articles on cbsim:

CB Simulator - Associated Software
... In October 1983 CBSIM CB Simulator was released as the first publicly accessible CB Simulator software available for privately-operated Computer Bulletin Board Systems ... Initially, CBSIM supported a maximum of 32 concurrent nodes (connected users), and allowed dynamic creation and cataloging of "channels" by the users ... The source code was released to the public from the inception of the CBSIM project, and this source code quickly became the foundation for multi-node chat systems embedded in other popular BBS ...