Introduction. A Formal View of Interfaces in a Multi-User Environment (A.A. Verrijn-Stuart). EuroPARC's Integrated Interactive Intermedia Facility (IIIF): Early Experiences (W. Buxton, T. Moran). Multi-User Interface Design. PAGES: A Testbed for Groupware Applications (R. Mantyla, J. Alasuvanto, H. Hammainen). A Formal Method for Specifying Temporal Properties of the Multi-User Interface (G.M. White). An Experiment in Distributed Group Problem Solving (G. De Koven, T. Radhakrishnan). The `User Illusion' Method in Multi-User Interface Design (Extended Abstract) (G. Lazarov, V. Lilov, M. Nikolova). Cooperative Development of Software. Group Work in Software Projects: Integrated Conceptual Models and Collaboration Tools (U. Hahn, M. Jarke, T. Rose). Collaborative Development of Software (M. Beaudouin-Lafon). A Cooperative Work Environment for Evolutionary Software Development (K. Kurbel, W. Pietsch). Shared Environments. Design of TeamWorkStation: A Realtime Shared Workspace Fusing Desktops and Computer Screens (H. Ishii, M. Ohkubo). The CATeam Meeting Room Environment as a Human-Computer Interface (H. Lewe, H. Krcmar). The Arizona Analyst Information System (K.J. Lynch et al.). Panel: Is Groupware a Passing Fad? Desktop Conferencing and Multi-User Editing. Elaborating Communication Channels in Conferencer (J.C. McCarthy, V.C. Miles). Design and Implementation of a PC/LAN-Based Multi-User Text Editor (M.O. Pendergast, D.R. Vogel). A Multi-User Document Review Tool (J.L. Koszarek et al.). A Proposed Model and Functionality Definition for a Collaborative Editing and Conferencing System (H. Lubich, B. Plattner). Messaging. MAFIA - An Active Mail-Filter-Agent for an Intelligent Document Processing Support (E. Lutz, H. v. Kleist-Retzow, K. Hoernig). Towards a Language for Defining Structure in Message-Based Cooperative Working (J. Dollimore, T. Roberts, G. Coulouris). A User Defined Environment for Handling Conversations (P. Gasparotti, C. Simone). Experiences with Multi-User Applications. Platform and Application Issues in Multi-User Hypertext (L.M. Berlin, V.L. O'Day). IBC and Cooperative Working in the Automotive Industry (S.E. Powrie, C.E. Siemieniuch). CNLS - Computer Network Lecturing System (P. Stanchev, V. Sabev). Coordination. An Architecture for Supporting Goal-Based Cooperative Work (N. Bhandaru, B. Croft). Influence of Exception Handling on the Support of Cooperative Office Work (B. Karbe, N. Ramsperger). Coordination of Intelligent Office Agents (M. Woitass).