This volume discusses "online" communities, where work is mediated and supported by a computer network. How do people react to spending much of their life online? What impacts does it have on the organization for productivity? The text addresses these issues by analyzing prototype systems of the mid 1980s that are desinged to provide answers to these questions in the future. The book should be of interest to those involved in the application and social impacts of computer-mediated communications systems and their design and evaluation inlcuding managers who must decide to implement such systems. It is also relevant for those interested in the relationship between technological innovation and soical change.