This paper focuses on the version models underlying both commercial systems and research prototypes. It provides an overview and classification of different versioning paradigms. Furthermore, it defines and relates fundamental concepts such as revisions, variants, configurations, and changes. In particular, we focus on intensional versioning, i.e., construction of versions based on configuration rules. Finally,we provide an overview of systems whichhave had significant impact on the development of the SCM discipline, and classify them according to a detailed taxonomy

. The ability to update a software system as it is being used is increasingly important and manifests itself in systems that must be maintained while executing, in systems where the choices about which components comprise a system are deferred until their use, and where systems can be customised. Systems that fit one or more of these characteristics we call dynamically composed systems. Although some attention has been given to providing tools to support dynamic updates, and models of such dynamic updates have been constructed, little work has been done in examining this from a configuration management perspective. This paper describes a model of configuration management for dynamically composed systems, based on an existing model of configuration management for statically configured systems. The model includes a dynamic configuration description language, DCDL, and a formalisation in terms of many-sorted algebraic specification techniques. The use of this model to design tools to supp...