[section:introduction Introduction]

Boost.MPI is a library for message passing in high-performance
parallel applications. A Boost.MPI program is one or more processes
that can communicate either via sending and receiving individual
messages (point-to-point communication) or by coordinating as a group
(collective communication). Unlike communication in threaded
environments or using a shared-memory library, Boost.MPI processes can
be spread across many different machines, possibly with different
operating systems and underlying architectures. 

Boost.MPI is not a completely new parallel programming
library. Rather, it is a C++-friendly interface to the standard
Message Passing Interface (_MPI_), the most popular library interface
for high-performance, distributed computing. MPI defines
a library interface, available from C, Fortran, and C++, for which
there are many _MPI_implementations_. Although there exist C++
bindings for MPI, they offer little functionality over the C
bindings. The Boost.MPI library provides an alternative C++ interface
to MPI that better supports modern C++ development styles, including
complete support for user-defined data types and C++ Standard Library
types, arbitrary function objects for collective algorithms, and the
use of modern C++ library techniques to maintain maximal
efficiency.

At present, Boost.MPI supports the majority of functionality in MPI
1.1. The thin abstractions in Boost.MPI allow one to easily combine it
with calls to the underlying C MPI library. Boost.MPI currently
supports:

* Communicators: Boost.MPI supports the creation,
  destruction, cloning, and splitting of MPI communicators, along with
  manipulation of process groups. 
* Point-to-point communication: Boost.MPI supports
  point-to-point communication of primitive and user-defined data
  types with send and receive operations, with blocking and
  non-blocking interfaces.
* Collective communication: Boost.MPI supports collective
  operations such as [funcref boost::mpi::reduce `reduce`]
  and [funcref boost::mpi::gather `gather`] with both
  built-in and user-defined data types and function objects.
* MPI Datatypes: Boost.MPI can build MPI data types for
  user-defined types using the _Serialization_ library.
* Separating structure from content: Boost.MPI can transfer the shape
  (or "skeleton") of complex data structures (lists, maps,
  etc.) and then separately transfer their content. This facility
  optimizes for cases where the data within a large, static data
  structure needs to be transmitted many times.

Boost.MPI can be accessed either through its native C++ bindings, or
through its alternative, [link mpi.python Python interface].

[endsect:introduction]