Primitives for Programming Multi-User Interfaces
P. Dewan and R. Choudhary
Nov 10, 1999
I found it valuable they approach of co-supporting collaboration-transparent and collaboration-aware.
The distinction between user and session is a very interesting point. It would allow collaborating with oneself. In this sense, it would be possible to support multiple points of view.
This approach is somehow an "OSI-style" collaboration, defining levels at both (or all) ends of the collaboration.