Piecemeal: a formal collaborative editing technique guaranteeing correctness
While collaboration on documents has been supported for several decades by a variety of systems and tools, in recent months a renewed interest is apparent through the appearance of new collaborative editors and applications. Some of these distributed groupware systems are plug-ins for standalone word processors, while others have a purely web-based existence. Most exemplars of the new breed of systems are based on Operational Transformations, although some are using traditional version management tools and still others utilize document-level locking techniques.
All current techniques have their own drawbacks, creating opportunities for new methods. In this paper we present a novel collaborative technique for documents which is based on transactions, schedulers, conflicts and locks. It is not meant to replace existing techniques; rather, it can be used in specific situations where the alternatives are less attractive. While our approach is highly formal with an emphasis on proving desirable properties such as guaranteed correctness, the work is part of a university-industry linkage project which aims to fully implement our technique.