With recent advances in networking and workstation technology, a variety of distributed multimedia applications are now becoming feasible, e.g. multimedia desktop conferencing and distance learning. However, the deployment of such applications has so far been rather limited. In the authors' opinion this limited deployment is largely explained by the immature state of distributed multimedia system support technologies rather than a lack of creativity on the part of application developers. The present paper therefore attempts to increase awareness of the relevant support technology issues by presenting a discussion of the state of the art in the key technologies of multimedia communications and distributed systems. It is argued that, while significant advances have been made on specific topics such as high performance transport protocols and real-time process scheduling in operating systems, considerable research is still required to produce a complete, integrated solution to the support of distributed multimedia applications.