============
[](https://travis-ci.org/LLNL/spack)
[](https://codecov.io/gh/LLNL/spack)
[](https://spack.readthedocs.io)
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](http://spack.readthedocs.io/en/latest/features.html)
for examples and highlights.
To install spack and your first package, make sure you have Python.
Then:
$ git clone https://github.com/llnl/spack.git
$ cd spack/bin
$ ./spack install libelf
Documentation
----------------
[**Full documentation**](http://spack.readthedocs.io/) for Spack is
the first place to look.
Try the
[**Spack Tutorial**](http://spack.readthedocs.io/en/latest/tutorial.html),
to learn how to use spack, write packages, or deploy packages for users
at your site.
See also:
* [Technical paper](http://www.computer.org/csdl/proceedings/sc/2015/3723/00/2807623.pdf) and
[slides](https://tgamblin.github.io/files/Gamblin-Spack-SC15-Talk.pdf) on Spack's design and implementation.
* [Short presentation](https://tgamblin.github.io/files/Gamblin-Spack-Lightning-Talk-BOF-SC15.pdf) from the *Getting Scientific Software Installed* BOF session at Supercomputing 2015.
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 Google Groups for this. Join here:
* [Spack Google Group](https://groups.google.com/d/forum/spack)
### Contributions
Contributing to Spack is relatively easy. Just send us a
[pull request](https://help.github.com/articles/using-pull-requests/).
When you send your request, make ``develop`` the destination branch on the
[Spack repository](https://github.com/LLNL/spack).
Your PR must pass Spack's unit tests and documentation tests, and must be
[PEP 8](https://www.python.org/dev/peps/pep-0008/) compliant. We enforce
these guidelines with [Travis CI](https://travis-ci.org/LLNL/spack). To
run these tests locally, and for helpful tips on git, see our
[Contribution Guide](http://spack.readthedocs.io/en/latest/contribution_guide.html).
Spack uses a rough approximation of the
[Git Flow](http://nvie.com/posts/a-successful-git-branching-model/)
branching model. The ``develop`` branch contains the latest
contributions, and ``master`` is always tagged and points to the latest
stable release.
Authors
----------------
Many thanks go to Spack's [contributors](https://github.com/llnl/spack/graphs/contributors).
Spack was created by Todd Gamblin, tgamblin@llnl.gov.
### Citing Spack
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**](http://www.computer.org/csdl/proceedings/sc/2015/3723/00/2807623.pdf).
In *Supercomputing 2015 (SC’15)*, Austin, Texas, November 15-20 2015. LLNL-CONF-669890.
Release
----------------
Spack is released under an LGPL license. For more details see the
LICENSE file.
``LLNL-CODE-647188``
