SAFMQ: Store and Forward Message Queue, message oriented middleware. Uses include Assured Async Messaging, SOA, Delayed/Batch, and Cluster/Grid Computing. The SAFMQ server provides cross platform communication among C++, PHP, Java, and .NET clients.
Dataflow parallel programminglanguage for clusters
PARUS is a data-flow parallel programminglanguage that allows to build parallel programs for clusters and MPP multiprocessors. The data-flow graph is automatically converted to the C++/MPI source and linked with the libparus runtime library.
Also there are available tools for benchmarking cluster interconnect and visualize it.