FNM Node Version Manager

FNM is a fast Node.js version manager written in Rust that installs and switches between multiple Node.js runtime versions on the same machine, designed as a lightweight alternative to nvm and n with significantly faster startup and switching performance. The tool distributes as a single compiled binary with no runtime dependencies, available for macOS, Windows, and Linux through package managers including Homebrew, Winget, Scoop, Chocolatey, and Cargo, or through a one-line shell installation script that downloads the prebuilt binary and configures the shell environment automatically. Version switching is driven by .node-version and .nvmrc files: when a developer changes into a project directory, FNM reads the version file and automatically activates the specified Node.js version, creating or switching to a cached installation without manual intervention. The --use-on-cd flag hooks into shell directory-change events to trigger this automatic switching in bash, zsh, fish, and PowerShell. Version installation downloads prebuilt binaries from the official Node.js distribution and caches them locally, with the multishell feature allowing different terminal sessions to run different Node.js versions simultaneously through isolated symlinks. The tool has over twenty-six thousand GitHub stars and one hundred eight contributors, with seventy releases published. Shell completions are generated on demand for bash, zsh, fish, and PowerShell. Configuration options control the Node.js mirror for downloads, the corepack enable behavior, and the log level. The command-line interface follows a verb-noun pattern with subcommands for install, use, list, default, current, env, and uninstall.