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Getting Started   •   Config   •   Community   •   Contributing   •   Packaging Guide

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 -c feature.manyFiles=true
$ cd spack/bin
$ ./spack install zlib


Full documentation is available, or run spack help or spack help --all.

For a cheat sheet on Spack syntax, run spack help --spec.


We maintain a hands-on tutorial. It covers basic to advanced usage, packaging, developer features, and large HPC deployments. You can do all of the exercises on your own laptop using a Docker container.

Feel free to use these materials to teach users at your organization about Spack.


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



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 our CI process. To run these tests locally, and for helpful tips on git, see our Contribution Guide.

Spack's develop branch has the latest contributions. Pull requests should target develop, and users who want the latest package versions, features, etc. can use develop.


For multi-user site deployments or other use cases that need very stable software installations, we recommend using Spack's stable releases.

Each Spack release series also has a corresponding branch, e.g. releases/v0.14 has 0.14.x versions of Spack, and releases/v0.13 has 0.13.x versions. We backport important bug fixes to these branches but we do not advance the package versions or make other changes that would change the way Spack concretizes dependencies within a release branch. So, you can base your Spack deployment on a release branch and git pull to get fixes, without the package churn that comes with develop.

The latest release is always available with the releases/latest tag.

See the docs on releases for more details.

Code of Conduct

Please note that Spack has a Code of Conduct. By participating in the Spack community, you agree to abide by its rules.


Many thanks go to Spack's contributors.

Spack was created by Todd Gamblin,

Citing Spack

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

On GitHub, you can copy this citation in APA or BibTeX format via the "Cite this repository" button. Or, see the comments in CITATION.cff for the raw BibTeX.


Spack is distributed under the terms of both the MIT license and the Apache License (Version 2.0). Users may choose either license, at their option.

All new contributions must be made under both the MIT and Apache-2.0 licenses.


SPDX-License-Identifier: (Apache-2.0 OR MIT)