CONCURRENCY AND COMPUTATION: PRACTICE AND EXPERIENCE Concurrency Computat.: Pract. Exper. 2002; 14:1543–1551 (DOI: 10.1002/cpe.680) A software development environment for Grid computing M. S. M ¨ uller ∗ ,† , E. Gabriel and M. M. Resch HLRS—High-Performance Computing Center Stuttgart, Allmandring 30, 70550 Stuttgart, Germany SUMMARY Grid computing has become a popular concept in the last few years. While in the beginning the driving force was metacomputing, the focus has now shifted towards resource management issues and concepts like ubiquitous computing. For the High-Performance Computing Center Stuttgart (HLRS) the key challenges of Grid computing have come from the demands of its users and customers. With high-speed networks in place, programmers expect to be able to exploit the overall performance of several instruments and high- speed systems for their applications. In order to meet these demands, HLRS has set out a research effort to provide these users with the necessary tools to develop and run their codes on clusters of supercomputers. This has resulted in the development of a basic Grid-computing environment for technical and scientific computing. In this paper we describe the building blocks of this software development environment and focus specifically on communication and debugging. We present the Grid-enabled MPI implementation PACX-MPI and the MPI debugger MARMOT. Copyright  2002 John Wiley & Sons, Ltd. KEY WORDS: MPI; Grid; software development OVERVIEW During the last five years the High-Performance Computing Center Stuttgart (HLRS) has set up a framework of collaborations and research projects in the field of Grid computing. All these efforts have circled around the central goal of enabling high-performance simulations on distributed supercomputers. With international high-speed networks in place, HLRS very early on tried to make ∗ Correspondence to: Matthias M ¨ uller, HLRS—High-Performance Computing Center Stuttgart, Allmandring 30, 70550 Stuttgart, Germany † E-mail: mueller@hlrs.de Contract/grant sponsor: Gigabit Testbed South Project; contract/grant number: DFN TK602-NT107 Contract/grant sponsor: METODIS, EU-Project Esprit; contract/grant number: 29909 Contract/grant sponsor: DAMIEN, EU-Project; contract/grant number: IST-2000-25406 Contract/grant sponsor: UNICORE Plus BMBF; contract/grant number: 01-IR-001 Contract/grant sponsor: DAAD Project; contract/grant number: 9922935 Received 23 July 2001 Copyright  2002 John Wiley & Sons, Ltd. Revised 6 January 2002