npm vs Spack

npm is a JavaScript package registry and command-line tool for sharing code and managing packages. The Registry and CLI are free for public package use, and the Free plan lets public package authors publish unlimited public packages. npm accepts package.json folders, gzipped tarballs, URLs, name-and-version or name-and-tag references, and Git URLs. Its tools support dependency resolution, lockfiles, workspaces, private registry authentication, and offline installation. It runs on Linux, macOS, Windows, and other operating systems through Node.js installers or version managers. For private packages, the Paid user account plan is $7 a month; Pro is also $7 a month for individual creators, while Teams is $7 per user per month for teams and organizations. Pro includes unlimited private packages and package-based permissions; Teams adds team-based permissions. Organizations can manage members, teams, roles, permissions, and package access. All plans include basic support and automatic security warnings. Paid billing starts when card details are submitted, with the first month charged immediately.

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.