4.2. Downloading Open MPI
Open MPI is generally available two ways:
- As source code. - The best place to get an official Open MPI source code distribution is from the main Open MPI web site. 
- Downstream Open MPI packagers (e.g., Linux distributions) sometimes also provide source code distributions. They may include additional patches or modifications. - Consult your favorite downstream packager for more details. 
 - Caution - Do not download an Open MPI source code tarball from GitHub.com. The tarballs automatically generated by GitHub.com are incomplete and will not build properly. - GitHub.com-generated tarballs are not official Open MPI releases. 
- As binary packages. - The Open MPI community does not provide binary packages on the main Open MPI web site. 
- Various downstream packagers (e.g., Linux distributions, Homebrew, MacPorts, etc.) do provide pre-built, binary packages for Open MPI. - Consult your favorite downstream packager for more details. 
 
The majority of the rest of this section deals with installing Open MPI from source.