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.TH "OPEN-MPI" "7" "Oct 09, 2026" "" "Open MPI"
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Open MPI \- General information
.SH OPEN MPI
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Open MPI is an open source implementation of MPI (message\-passing
interface), the industry\-standard specification for writing
message\-passing programs. Message passing is a programming model that
gives the programmer explicit control over interprocess communication.
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The MPI specification was developed by the MPI Forum, a group of
software developers, computer vendors, academics, and computer\-science
researchers whose goal was to develop a standard for writing
message\-passing programs that would be efficient, flexible, and
portable.
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The outcome, known as the MPI Standard, was first published in 1993; its
most recent version (MPI\-4.0) was published in June 2021. Open MPI
includes all MPI 3.1\-compliant routines.
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For more information about Open MPI, see \%<https://\:www\:.open-mpi\:.org>\&.
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The MPI standards are available at \%<https://\:www\:.mpi-forum\:.org>\&.
.SH MAN PAGE SYNTAX
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Man pages for Open MPI and Open MPI I/O routines are named according to
C syntax, that is, they begin with the prefix \fBMPI_\fP, all in
uppercase, and the first letter following the \fBMPI_\fP prefix is also
uppercase. The rest of the letters in the routine are all lowercase, for
example, MPI_Comm_get_attr \%<#\:mpi-comm-get-attr>\&.
.SH ENVIRONMENT
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To fine\-tune your Open MPI environment, you can either use arguments
to the mpirun \%<#\:man1-mpirun> or mpiexec \%<#\:man1-mpiexec>
commands, or you can use MCA parameters.
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For more information on arguments, see the mpirun(1) \%<#\:man1-mpirun> man page.
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For a complete listing of MCA parameters and their descriptions, issue
the command \fBompi_info \-\-all\fP\&.  See ompi_info(1) \%<#\:man1-ompi-info> for more information.
.SH ERRORS
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See MPI Errors \%<#\:mpi-errors> for details about error values.
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\fBSee also:\fP
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MPI_T \%<#\:mpi-t> mpirun(1) \%<#\:man1-mpirun> mpiexec(1) \%<#\:man1-mpiexec> ompi_info(1) \%<#\:man1-ompi-info>
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.SH Copyright
2003-2026, The Open MPI Community
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