Modelling versions in collaborative work

The problem of version management for co-operative systems is addressed. The authors first describe a basic version model-a domain model capturing the idea of a version and the relationships between versions, whether electronic or physical, implicitly or explicitly stored. This is a `modal´ model in that it takes into account the context of use of these versions. The model is then extended to model version managers, which are both versioned entities themselves and also include their own models of versions. Finally, the authors show how V-Web, a system for versioning Web pages, fits within the framework of the model