Computer supported cooperative work
Computer supported cooperative work or CSCW is the name of the formal field of usability, productivity and other studies of multi-user interface design. This includes what is now called groupware and social software and of course large public wikis.
CSCW "is the study of how people work together using computer technology. Typical applications include email, awareness and notification systems, videoconferencing, chat systems, multi-player games, and realtime shared applications (such as collaborative writing or drawing)"
There have been major conferences on this subject for decades held by ACM and ECSCW and COOP
Eighth ECSCW conference in Helsinki, September 2003
CSCW 2004 in Chicago in November, 2004 - MOST important
groupware resources - EXCELLENT