elan vs nvm

elan manages installations of the Lean theorem prover on Linux, macOS and Windows. Its `lean` and `lake` binaries use a project’s `lean-toolchain` file to select the specified Lean version and download it when needed. The separate `elan` command provides manual control to install, select, run or uninstall Lean versions. The project supports version pinning, lockfiles, automatic switching, shell integration and CI/CD use. Installation options include shell instructions for Linux and macOS, a PowerShell method for Windows, and release downloads for supported platforms. The README recommends the Nixpkgs version on NixOS because toolchains downloaded by elan require patching there. Lake needs git to download dependencies. The project describes itself as a fork of rustup adapted for Lean infrastructure. elan is free at free, and the repository lists Apache-2.0 and MIT licenses. The releases page identifies v4.2.4 as the latest release.

nvm is a free, MIT-licensed command-line tool for installing and managing Node.js versions. It is designed for installation per user and invocation per shell, and works in POSIX-compliant shells including sh, dash, ksh, zsh, and bash. Users can install specific versions, switch between them, set aliases such as a default, and use LTS aliases and commands to select long-term support versions. A project can specify its Node.js version in an.nvmrc file; documented shell snippets can support automatic switching. During installation, nvm can reinstall global npm packages from another installed Node.js version. With the --offline flag, it can install a version that was previously downloaded or cached without network access. The project documents use in Docker, including an example for CI/CD jobs. On Windows, nvm can work through WSL and may work with Git Bash or Cygwin depending on the environment. Fish shell is not supported, and the project points users to community alternatives. The project states that only the latest nvm version is supported.