Spack is a multi-platform package manager that builds and installs multiple versions and configurations of software. It works on Linux, macOS, and many supercomputers. Spack is non-destructive: installing a new version of a package does not break existing installations, so many configurations of the same package can coexist.

Spack offers a simple "spec" syntax that allows users to specify versions and configuration options. Package files are written in pure Python, and specs allow package authors to write a single script for many different builds of the same package. With Spack, you can build your software all the ways you want to.

See the Feature Overview for examples and highlights.

To install spack and your first package, make sure you have Python. Then:

$ git clone https://github.com/spack/spack.git
$ cd spack/bin
$ ./spack install libelf

Full documentation for Spack is the first place to look.

Try the Spack Tutorial, to learn how to use spack, write packages, or deploy packages for users at your site.

See also:

• Technical paper and slides on Spack's design and implementation.
• Short presentation from the Getting Scientific Software Installed BOF session at Supercomputing 2015.

Spack is an open source project. Questions, discussion, and contributions are welcome. Contributions can be anything from new packages to bugfixes, or even new core features.

If you are interested in contributing to spack, join the mailing list. We're using Google Groups for this:

• Spack Google Group

Spack has a Slack channel where you can chat about all things Spack:

• Spack on Slack

Sign up here to get an invitation mailed to you.

Contributing to Spack is relatively easy. Just send us a pull request. When you send your request, make develop the destination branch on the Spack repository.

Your PR must pass Spack's unit tests and documentation tests, and must be PEP 8 compliant. We enforce these guidelines with Travis CI. To run these tests locally, and for helpful tips on git, see our Contribution Guide.

Spack uses a rough approximation of the Git Flow branching model. The develop branch contains the latest contributions, and master is always tagged and points to the latest stable release.

Many thanks go to Spack's contributors.

Spack was created by Todd Gamblin, [email protected].

If you are referencing Spack in a publication, please cite the following paper:

• Todd Gamblin, Matthew P. LeGendre, Michael R. Collette, Gregory L. Lee, Adam Moody, Bronis R. de Supinski, and W. Scott Futral. The Spack Package Manager: Bringing Order to HPC Software Chaos. In Supercomputing 2015 (SC’15), Austin, Texas, November 15-20 2015. LLNL-CONF-669890.

Spack is released under an LGPL license. For more details see the NOTICE and LICENSE files.

LLNL-CODE-647188