The client-server architecture is widely used in the construction of virtual environments because it allows specific services to be provided to the connected clients and management tasks to be performed, such as reducing the network load by performing message filtering. The majority of client-server systems are incompatible with each other, both in terms of hardware and software. In particular, the different communication protocols make the cooperation between the various systems difficult. This paper guides the reader through the construction and implementation of a server that consists of clearly distinct components, developed to reflect a reference model for a generic and open client-server system. This server, employed in the PAVR network, not only allows incompatible clients and applications to be linked into a common environment with little effort, but, in addition, the detailed description of its implementation can provide valuable help to whoever undertakes the task of coding such systems.