Part 1 Designing a collaborative workspace: introduction; designing at a distance - experiments in remote-synchronous design; design principles for sharing in Tivoli, a whiteboard meeting-support tool; human and technical factors of distributed group drawing tools; gesturing through cursors - implementing multiple pointers in group support systems; using a shared pen-based tool for meeting support; integration of interpersonal space and shared workspace - clear-board design and experiments. Part 2 Systems, architectures and toolkits for groupware: introduction; WSCRAWL 2.0 - a shared whiteboard based on X-Windows; GroupKit - a groupware toolkit for building real time conferencing applications; SLICE - a logical model for shared editors.