A flexible package manager that supports multiple versions, configurations, platforms, and compilers.
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Spack is a package management tool designed to support multiple versions and configurations of software on a wide variety of platforms and environments. It was designed for large supercomputing centers, where many users and application teams share common installations of software on clusters with exotic architectures, using libraries that do not have a standard ABI. Spack is non-destructive: installing a new version does not break existing installations, so many configurations can coexist on the same system.

Most importantly, Spack is simple. It offers a simple spec syntax so that users can specify versions and configuration options concisely. Spack is also simple for package authors: package files are written in pure Python, and specs allow package authors to write a single build script for many different builds of the same package.

See the Feature Overview for examples and highlights.

To install spack and install your first package:

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


Full documentation for Spack is the first place to look.

We've also got a Spack 101 Tutorial, so you can learn Spack yourself, or teach users at your own site.

See also:

Get Involved!

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.

Mailing list

If you are interested in contributing to spack, the first step is to join the mailing list. We're using a Google Group for this, and you can join it here:


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 originally written by Todd Gamblin, tgamblin@llnl.gov.

Citing Spack

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


Spack is released under an LGPL license. For more details see the LICENSE file.