JJPF (the Java/Jini Parallel Framework) is a framework that can run stream parallel applications on several parallel-distributed architectures. JJPF is a distributed execution server, actually. It uses JINI to recruit the computational resources needed to compute parallel applications. Parallel applications can be run on JJPF provided they exploit parallelism accordingly to an arbitrary nesting of task farm and pipeline skeletons/patterns. JJPF achieves almost perfect, fully automatic load balancing in the execution of such kind of applications. It also transparently handles any number of node and network faults. Scalability and efficiency results are shown on workstation networks, both with a synthetic (embarrassingly parallel) image processing application and with a real (not embarrassingly parallel) page ranking application.