Multiuser processes and shared capability lists for shared workspace collaboration

With the recent interest in collaboration software and tools, there is a growing need and demand for operating systems to support and facilitate the construction of this new application. This article investigates desirable features for shared workspaces and discusses the relevance of operating systems supporting them. Two operating system mechanisms are proposed to support multiuser tool development and sharing of user privileges in a collaborative session. The first mechanism, multiuser processes, is a generalization of traditional operating system processes. The second mechanism, shared capabilities lists, is used to achieve finer control of object sharing among participants. An initial prototype implementation based on BSD 4.3 UNIX is described. Implementation alternatives and associated issues are discussed.