Spack vs Yarn

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.

Yarn is a package manager and project manager for JavaScript projects, serving uses from simple projects to industry monorepos. It resolves dependencies, maintains lockfiles and provides workspaces that install and link packages within a project. Modern Yarn uses Plug'n'Play by default, generating a Node.js loader file instead of a typical node_modules folder; users can choose node_modules or pnpm-style symlink installs instead. Yarn caches installed packages and shares them among projects on the same machine. Its offline mirror and zero-installs workflow can keep cached packages in a repository and reduce reliance on the npm registry. Plugins can extend resolvers, fetchers, linkers, commands and lifecycle hooks. Generated editor SDKs and settings support VSCode, Vim, Emacs and Neovim. Yarn runs on Linux, macOS and Windows and is free, with no paid plans or usage limits stated. Its documentation notes that React Native and Expo require typical node_modules installs. Yarn does not run audits during installation by default; users can run yarn npm audit separately.