Spack vs uv

Spack is a package manager for installing scientific software on supercomputers, Linux, macOS, and Windows. It is designed for large supercomputing centers that share software across clusters and varied architectures, and is available at free. Users can choose package versions, compiler choices, target architectures, and compile-time options, while controlling direct and transitive dependencies. Spack can build stacks that combine Python or R packages with C, C++, or Fortran libraries. Each distinct package and dependency configuration receives its own prefix, so different builds can coexist without a new installation disrupting an existing one. Software can be installed to a user-selected directory without administrator privileges. Spack primarily builds customized software from source and also supports binary installation through build caches. It supports lockfiles, environment management, and private registries. Package recipes are Python scripts, and the `spack create` command generates starter boilerplate. The project is distributed under either the MIT license or Apache License 2.0, at the user's option.

uv is a Python package and project manager for Linux, macOS, and Windows. Written in Rust, it manages dependencies and environments, with lockfiles and workspaces, and can install, list, pin, or uninstall Python versions. It also runs scripts with dependencies and runs or installs command-line tools from Python packages. Its pip-compatible interface is intended to cover work done by tools such as pip, pip-tools, pipx, poetry, pyenv, twine, and virtualenv, though its commands do not exactly match those tools. The documentation describes uv as 10–100x faster than pip. It supports source distributions, wheels, requirements.txt, and pylock.toml, as well as offline installation and private registry authentication. For package selection, its default first-index strategy limits candidates to the first index where a package is found. Credentials are not stored in uv.lock, but uv currently stores them in a plaintext file; native system secret storage is an experimental preview. The free plan is free.