Wikipedia
Split-C
Split-C is a parallel extension of the C programming language. The Split-C project website describes Split-C as:
a parallel extension of the C programming language that supports efficient access to a global address space on current distributed memory multiprocessors. It retains the "small language" character of C and supports careful engineering and optimization of programs by providing a simple, predictable cost model.
Development of Split-C appears to be at a standstill since 1996. Split-C is similar to Cilk.