# 16. History of Open MPI

Open MPI represents the merger of three prior MPI implementations:

1. LAM/MPI: originally from the Ohio State University supercomputing center and later migrated to the University of Notre Dame.

2. LA-MPI: from the US Department of Energy Los Alamos National Laboratory.

3. FT-MPI: from the University of Tennessee at Knoxville. One of the UTK developers moved back to the University of Stuttgart in late 2004, which effectively added their team into the project.

The lead developers of these projects kept bumping into each other at various HPC conferences in 2003. At each conference, our lunch/dinner-table conversations got more and more technically involved when it finally dawned on us that we are doing a lot of the same things in each of our respective implementations. Although each MPI implementation focused on different areas of excellence, we all shared the same common core values:

- A full MPI implementation

- Production quality code — it has to “just work”

- A desire to explore lots of things that an MPI implementation can do that we’ve never had the time/resources to investigate because we are bound to bug fixing, etc.

Hence, we decided to collaborate and pool our resources. At SC2003, we decided to start an entire new code base — leaving all the cruft and legacy code of our prior implementations behind. Take the best, leave the rest. The source tree’s first commit was on November 22, 2003; development work started in earnest on January 5, 2004. Since then, we have met together as a group once a month (for at least a week) to meet our goal of a world-class MPI implementation, bar none.

## 16.1. Goals of the Open MPI Project

We have several top-level goals:

1. Create a free, open source, peer-reviewed, production-quality complete MPI implementation.

2. Provide extremely high, competitive performance (latency, bandwidth, …pick your favorite metric).

3. Directly involve the HPC community with external development and feedback (vendors, 3rd party researchers, users, etc.).

4. Provide a stable platform for 3rd party research and commercial development.

5. Support a wide variety of HPC platforms and environments.

In short, we want to work with and for the HPC community to make a world-class MPI implementation that can be used on a huge number and kind of systems.

## 16.2. Community

Bringing together smart researchers and developers to work on a common product is not only a good idea, it’s the open source model. The Open MPI project started by multiple MPI implementation teams, and that proved to work extremely well; extending this concept to the HPC open source community is the next logical step.

The component architecture upon which Open MPI is founded is designed to foster 3rd party collaboration by enabling independent developers to use Open MPI as a production quality research platform. Although Open MPI is a relatively large code base, it is not necessary to learn the entirety of it; it may be sufficient to learn the interfaces for the component type which you are implementing and some of the surrounding infrastructure. Specifically, the component architecture was designed to allow small, discrete implementations of major portions of MPI functionality (e.g., point-to-point messaging, collective communications, run-time environment support, etc.).