HP-MPI for Microsoft Windows Compute Cluster Server 2003 and Windows XP Professional is a high performance and production quality implementation of the Message-Passing Interface (MPI) standard for HP servers and workstations. HP-MPI uses enhancements whenever appropriate to provide low latency and high bandwidth point-to-point and collective communication routines. It supports multi-protocol execution of MPI applications on clusters of shared-memory servers so that applications can take advantage of the shared memory for intra-node communications. HP-MPI supports multiple interconnects and enables the customer to build a single executable that transparently takes advantage of the supported high performance interconnects. This greatly reduces the efforts of customers and Independent Software Vendors (ISVs) to make their applications available on the latest and greatest interconnect technologies on Linux, HP-UX and Microsoft Windows. HP customers have been benefiting from HP-MPI on HP-UX clusters for a decade. Users choosing HP-MPI for Microsoft Windows now have a high performance and production ready MPI implementation on industry standard servers.