PALS: An or-parallel implementation of prolog on beowulf architectures

Abstract. This paper describes the development of the PALS system, an implementation of Prolog that efficiently exploits or-parallelism on share-nothing platforms. PALS makes use of a novel technique, called incremental stack-splitting. The technique builds on the stack-splitting approach, which in turn is an evolution of the stack-copying method used in a variety of parallel logic systems. This is the first distributed imple-mentation based on the stack-splitting method ever realized. Experimen-tal results obtained on a Beowulf system are presented and analyzed.