John M. Dennis Computer Information and Systems Laboratory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, Colorado 80307 (dennisncar.edu). Dr. Dennis received his Ph.D. degree in computer science from the University of Colorado at Boulder. He studied the memory efficiency of Krylov iterative algorithms. He is one of the Chief Architects and the Lead Developer of the HOMME framework. Dr. Dennis's work has been recognized with an honorable mention Gordon Bell Prize in 2001 for excellence in high-performance supercomputing. His interests include high-performance parallel computing, mesh partitioning, computer architecture, iterative algorithms, and language processing.

Henry M. Tufo Computer Information and Systems Laboratory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, Colorado 80307 (tufoncar.edu). Dr. Tufo received his Ph.D. degree from Brown University in 1998, and he is currently an Associate Professor of computer science at the University of Colorado and leads the Computer Science Section in the Computational and Information Systems Laboratory at the National Center for Atmospheric Research. Dr. Tufo conducts research in high-performance computing, parallel algorithms and architectures, high-order numerical methods, scalable solvers, computational fluid dynamics, atmospheric science, scientific visualization, Linux** cluster technology, and grid computing. Dr. Tufo's work has been recognized with Gordon Bell Prizes in 1999 and 2000 for demonstrated excellence in high-performance supercomputing.

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