José E. Moreira IBM Systems and Technology Group, 3605 Highway 52 N., Rochester, Minnesota 55901 (jmoreira@us.ibm.com). Dr. Moreira received B.S. degrees in physics and electrical engineering in 1987 and an M.S. degree in electrical engineering in 1990, all from the University of São Paulo, Brazil. He received his Ph.D. degree in electrical engineering from the University of Illinois at Urbana–Champaign in 1995. Since joining IBM in 1995, he has been involved in several high-performance computing projects, including the teraflop-scale ASCI Blue-Pacific, ASCI White, and Blue Gene/L. Dr. Moreira was a manager at the IBM Thomas J. Watson Research Center from 2001 to 2004; he is currently the Lead Software Systems Architect for the IBM eServer Blue Gene solution. Dr. Moreira is the author of more than 70 publications on high-performance computing. He has served on various thesis committees and has been the chair or vice-chair of several international conferences and workshops. Dr. Moreira interacts closely with software developers, hardware developers, system installers, and customers to guarantee that the delivered systems work effectively and accomplish their intended missions successfully.

George Almási IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (gheorghe@us.ibm.com). Dr. Almási is a Research Staff Member at the IBM Thomas J. Watson Research Center. He received an M.S. degree in electrical engineering from the Technical University of Cluj-Napoca, Romania, in 1991 and an M.S. degree in computer science from West Virginia University in 1993. In 2001 he received a Ph.D. degree in computer science from the University of Illinois at Urbana–Champaign; his thesis dealt with ways of optimizing and compiling MATLAB code. For the last three years, Dr. Almási has been working on various aspects of the Blue Gene system software environment, including the MPI communication libraries.

Charles Archer IBM Systems and Technology Group, 3605 Highway 52 N., Rochester, Minnesota 55901 (archerc@us.ibm.com). Mr. Archer is a software engineer working on the Blue Gene/L project. He received a B.S. degree in chemistry and a B.A. degree in mathematics from Minnesota State University at Moorhead, and an M.S. degree in chemistry from Columbia University. He is currently a graduate student in computer science at the University of Minnesota. Mr. Archer has worked on the OS/400* PASE project and grid computing. His current role is development, optimization, and maintenance of the Blue Gene/L message-passing software stack.

Ralph Bellofatto IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (ralphbel@us.ibm.com). Mr. Bellofatto is a Senior Software Engineer. He has been responsible for various aspects of hardware system verification and control system programming on the Blue Gene/L project. He received B.S. and M.S. degrees from Ithaca College in 1979 and 1980, respectively. He has worked as a software engineer in a variety of industries. Mr. Bellofatto's interests include computer architecture, performance analysis and tuning, network architecture, ASIC design, and systems architecture and design. He is currently working on the control system for Blue Gene/L.

Peter Bergner IBM Systems and Technology Group, 3605 Highway 52 N., Rochester, Minnesota 55901 (bergner@us.ibm.com). Dr. Bergner is a member of the Blue Gene/L software team working on compiler and runtime library development. He received a Ph.D. degree in electrical engineering from the University of Minnesota in 1997. His thesis work involved developing techniques for minimizing spill code in graph coloring register allocators. Dr. Bergner has worked in a variety of areas since joining IBM, including AS/400* compiler optimizer development and Linux kernel and compiler development for PowerPC hardware platforms.

José R. Brunheroto IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (brunhe@us.ibm.com). Mr. Brunheroto is a Senior Software Engineer at the IBM Thomas J. Watson Research Center. He received a B.S. degree in electrical engineering from Escola Politécnica, University of São Paulo, Brazil. Mr. Brunheroto is currently working on his M.A. degree in computer science at Columbia University. His research interests include computer architecture, simulators (single-node and distributed), and performance tools.

Michael Brutman IBM Systems and Technology Group, 3605 Highway 52 N., Rochester, Minnesota 55901 (brutman@us.ibm.com). Mr. Brutman has worked for IBM since 1992. Before joining the Blue Gene project in early 2003, he concentrated on operating systems implementation and performance analysis. Mr. Brutman has worked primarily on the control system and debugger support for the compute node kernel as part of the Blue Gene team.

José Gabriel Castaños IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (castanos@us.ibm.com). Dr. Castaños joined the Blue Gene project in 2000 after receiving his Ph.D. degree in computer science at Brown University. His initial assignment as a Research Staff Member involved the development of applications for high-performance computing. He later became one of the technical leaders of the Blue Gene/L systems software and worked on many of its components: integrated software development environment, simulators, kernels, runtime libraries, and management infrastructure. Dr. Castaños received his undergraduate degrees in systems analysis (1988) and operations research (1989) at the Universidad Católica, Buenos Aires, Argentina.

Paul G. Crumley IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (pgc@us.ibm.com). Mr. Crumley has worked in the IBM Research Division for more than 20 years. His work and interests span a wide range of projects including distributed data systems, high-function workstations, operational processes, and, most recently, cellular processor support infrastructure.

Manish Gupta IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (mgupta@us.ibm.com). Dr. Gupta is a Research Staff Member and Senior Manager of the Emerging System Software Department at the IBM Thomas J. Watson Research Center. His group has developed system software for the Blue Gene/L machine and conducts research on software issues for high-performance server systems. In 1992 he received a Ph.D. degree in computer science from the University of Illinois at Urbana–Champaign and has worked with the IBM Research Division since then. Dr. Gupta has coauthored several papers in the areas of high-performance compilers, parallel computing, and high-performance Java** Virtual Machines.

Todd Inglett IBM Systems and Technology Group, 3605 Highway 52 N., Rochester, Minnesota 55901 (tinglett@us.ibm.com). Mr. Inglett graduated with a B.S. degree in computer science from the University of Wisconsin in 1987, joining ETA Systems, Inc., as a software engineer. He began work at IBM in Rochester, Minnesota, in 1989, and was part of the Andrew Project and Andrew Consortium as a partner with Carnegie Mellon University from 1989 to 1993. He then worked on IBM internal development tools, including Apache, from 1994 to 1998, and on porting Linux to the PowerPC 64-bit architecture from 1999 to 2002. Mr. Inglett has been a member of the Blue Gene/L software development team since 2002. He has made various contributions to the project, including the I/O node Linux kernel, parts of the control system, file system performance, and system bring-up.

Derek Lieber IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (lieber@us.ibm.com). Mr. Lieber received his B.S. degree in physics from Lebanon Valley College in 1975. In 1983 he joined the IBM Thomas J. Watson Research Center, where he is currently a Senior Software Engineer. Mr. Lieber was the technical leader and main implementer of the Jikes Research Virtual Machine (RVM) runtime environment. The Jikes RVM has been recognized by institutions worldwide as a excellent platform for research in Java. He was the main designer and implementer of the Blue Gene/L operating environment. Mr. Lieber has more than 20 publications in high-performance computing.

David Limpert IBM Systems and Technology Group, 3605 Highway 52 N., Rochester, Minnesota 55901 (limpert@us.ibm.com). Mr. Limpert is a Senior Technical Staff Member responsible for the software development and delivery of the Blue Gene/L supercomputer system. In 1977 he joined IBM in Rochester, Minnesota, after receiving a B.A. degree in mathematics and computer science from Saint Mary's University of Minnesota. He has a wide range of experience in the field of systems software engineering. His areas of responsibility have ranged from design and implementation of microcode for terminal and server system devices to technical project leader for complete software systems. During the 1980s and early 1990s, he led software development teams in the integration of the emerging PC business with IBM midrange server systems as cooperative processing workstations. Those efforts progressed from simple terminal device emulators to full-feature distributed processing networked environments. Mr. Limpert shifted focus in the late 1990s to the design of network-connected thin clients and their use of Linux as an embedded operating system.

Patrick McCarthy IBM Systems and Technology Group, 3605 Highway 52 N., Rochester, Minnesota 55901 (pjmccart@us.ibm.com). Mr. McCarthy has worked for IBM since 1984 and has spent most of his career in kernel development, including the OS/400 kernel and microkernel and the Linux port to the 64-bit PowerPC. He is currently working on the development of the BG/L supercomputer. His main focus is on the kernels which run on the compute and I/O nodes in the Blue Gene/L system. Mr. McCarthy has also worked on the development of parts of the Blue Gene/L control system.

Mark Megerian IBM Systems and Technology Group, 3605 Highway 52 N., Rochester, Minnesota 55901 (megerian@us.ibm.com). Mr. Megerian is a Senior Software Engineer in the IBM Rochester Laboratory. He graduated from Michigan State University with a degree in computer science in 1987, joining IBM upon graduation. His past responsibilities have included database and SQL development on the iSeries* platform. Mr. Megerian is currently the control system team leader for BlueGene/L.

Mark Mendell IBM Software Group, Toronto Laboratory, 8200 Warden Avenue, Markham, Ontario, Canada L6G 1C7 (mendell@ca.ibm.com). Mr. Mendell graduated from Cornell University in 1980 with a B.S. degree in computer engineering. He received his M.S. degree in computer science from the University of Toronto in 1983. At the University of Toronto, he helped develop the Concurrent Euclid, Turing, and Turing Plus compilers, and worked on the Tunis operating system project. In 1991 he joined IBM, working initially on the AIX* C++ compiler from V1.0 to V5.0. He has been the team leader for the TOBEY Optimizer Group since 2000. Mr. Mendell implemented the automatic compiler support of the dual floating-point unit (FPU) for the Blue Gene/L project.

Michael Mundy IBM Systems and Technology Group, 3605 Highway 52 N., Rochester, Minnesota 55901 (mmundy@us.ibm.com). Mr. Mundy joined IBM in 1989 as a developer and tester for the MVS operating system. His past projects have included Qshell (a shell and utilities package), base POSIX enablement, Pthreads, TCP/IP sockets, and the Distributed Computing Environment (DCE). Since 1993 he has worked on i5/OS* and its predecessors to provide open industry-standard interfaces. Mr. Mundy is currently working on the compute node kernel of Blue Gene/L.

Don Reed IBM Systems and Technology Group, 3605 Highway 52 N., Rochester, Minnesota 55901 (donreed@us.ibm.com). Mr. Reed received his computer science degree from the University of South Dakota. At IBM he has worked on control systems for DASD manufacturing, the port of Linux to 64-bit PowerPC, and process and resource management for the OS/400 kernel. His current role is development and maintenance of the hardware initialization and control system software stack of Blue Gene/L.

Ramendra K. Sahoo IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (rsahoo@us.ibm.com). Dr. Sahoo received a B.E. degree (with honors) in mechanical engineering from the National Institute of Technology, Durgapur, India, in 1990, and an M.S. degree (research) from the Indian Institute of Technology, Chennai, in 1992. In 1998 he received his Ph.D. degree from the State University of New York at Stony Brook. Prior to joining the Ph.D. program at Stony Brook, he worked as an assistant manager (CAD and analysis) at TATA Motors Engineering Research Center. Since 2000 he has worked at the IBM Thomas J. Watson Research Center and is currently a member of the Blue Gene Systems Software Group. Dr. Sahoo's research interests include distributed and fault-tolerant computing, numerical and parallel algorithms, databases, and artificial intelligence. He has published 35 papers in refereed international journals and conferences in the area of scientific computing, electronic packaging, data mining, parallel computing, and artificial intelligence. Dr. Sahoo holds seven patents in the area of distributed and fault-tolerant computing; he is a member of the IEEE and ASME.

Alda Sanomiya IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (sanomiya@us.ibm.com). Mrs. Sanomiya received a B.S. degree in computer science from the Universidade de São Paulo, Brazil. She began working with IBM Brazil in 1986 and joined the IBM Research Division in 2000. Mrs. Sanomiya was responsible for the first port of Linux to the Blue Gene/L I/O nodes; she has also worked on control systems for the Blue Gene/L project.

Richard Shok IBM Systems and Technology Group, 3605 Highway 52 N., Rochester, Minnesota 55901 (shok@us.ibm.com). Mr. Shok has worked for IBM for more than six years. During that time, he has been involved in OS internals, retail middleware, and custom programs for various IBM customers. Mr. Shok has spent the last year working on the Blue Gene/L project; he is primarily responsible for software builds, integration, and packaging.

Brian Smith IBM Systems and Technology Group, 3605 Highway 52 N., Rochester, Minnesota 55901 (smithbr@us.ibm.com). Mr. Smith has worked at IBM in Rochester, Minnesota, for the past year as a co-op student. His work primarily involves MPI development and optimization, and porting applications for Blue Gene/L. In early 2005 he began working full-time at IBM Rochester, after graduating from Iowa State University with an M.S. degree in computer engineering.

Gordon G. (Greg) Stewart IBM Systems and Technology Group, 3605 Highway 52 N., Rochester, Minnesota 55901 (gregstewt@us.ibm.com). Mr. Stewart is a Senior Software Engineer in the eServer Custom Technology Center at IBM in Rochester, Minnesota. He received a B.S. degree in mathematics and an M.S. degree in computer science from Northern Illinois University in 1974 and 1976, respectively. After spending two years at Baxter/Travenol Laboratories as a systems programmer, Mr. Stewart joined IBM in 1978 to work on the development of the IBM System/38*. Since then, he has worked chiefly in architecture and development in various areas of the System/38, AS/400, and iSeries operating systems, particularly in data communications, availability/recovery, and the POSIX and C language environments. He has also contributed to the development of several application middleware products, including Domino* for AS/400 and Net.Data*. In 2000 he joined the eServer Custom Technology Center, where he has worked on the Blue Gene/L project, primarily in development of the control system. Mr. Stewart has received several patents and IBM Technical Achievement Awards.

*Trademark or registered trademark of International Business Machines Corporation.
**Trademark or registered trademark of Sun Microsystems, Inc. in the United States, other countries, or both.