The work described in this report has benefited from conversations with and use by a large number of people. We also thank those that have helped in the implementation of MPICH, particularly Patrick Bridges and Edward Karrels. Particular thanks goes to Nathan Doss and Anthony Skjellum for valuable help in the implementation and development of MPICH. More recently, Debbie Swider has joined the MPICH team. The Globus device was implemented by Nick Karonis of Northern Illinois University. The C++ bindings were implemented by Andrew Lumsdaine and Jeff Squyres of the University of Notre Dame. The ROMIO MPI-2 parallel I/O subsystem was implemented by Rajeev Thakur of Argonne.