The de-facto standard for programming distributed memory parallel architectures are the PVM and MPI message passing libraries. Their low level of abstraction makes the programmers task error-prone and reduces application portability. SODA is a novel programming model that presents a much higher level of abstraction and manages most low-level distribution and parallelism details implicitly. SODA is based on an extension of the active objects paradigm. This work is structured into two main parts. In the first part we present a novel data-flow synchronisation mechanism for active objects that...