A flexible package manager that supports multiple configurations.
                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.