We live in the era of the internet which makes it possible to connect more and more people to each other. For this large amount of users suitable technologies are needed, so users can collaborate with each other efficiently. The solution should be able to cover the complex details and problems which can occur in large systems, like concurrent access to data. The newly developed middleware XVSM (eXtensible Virtual Shared Memory) that is based on shared data structures enables an efficient solution for many real-world problems. The XVSM model allows an intuitive collaboration between different partners on a peer-to-peer infrastructure. For coordination the model supports flexible data structures that can easily be customized. Another strength of this lightweight system is that the middleware can also be used on mobile devices. The biggest advantage of XVSM is the extensibility of the module structure. New functionalities can be included very quickly to the core system.
As a basis for the descriptions in this thesis the XcoSpaces, the .NET reference implementation of XVSM, is used. The focus in this thesis lies on three main issues, which are the coordination concept, transactions and communication. First of all, many possibilities for the whole coordination mechanism are shown. The transaction and locking management allows concurrent access to data without inconsistencies. The middleware is able to communicate across machine boundaries via communication services.