Programming models and languages for high-productivity computing systems

High performance computing (HPC) provides the superior computational capability required for dramatic advances in key areas of science and engineering such as DNA analysis, drug design, or structural engineering. Over the past decade, progress in this area has been threatened by technology problems that pose serious challenges for continued advances in this field. One of the most important problems has been the lack of adequate language and tool support for programming HPC architectures. In today's dominating programming paradigm users are forced to adopt a low level programming style similar to assembly language if they want to fully exploit the capabilities of parallel machines. This leads to high cost for software production and error-prone programs that are difficult to write, reuse, and maintain. This paper discusses the option of providing a high-level programming interface for HPC architectures. We summarize the state of the art, describe new challenges posed by emerging peta-scale systems, and outline features of the Chapel language developed in the DARPA-funded Cascade project.