fnm vs Jabba

fnm is a free Node.js version manager built in Rust for developers working from a command line or shell. It runs on macOS, Windows, and Linux, and is distributed as a single file through installation scripts, package managers, Cargo, or release binaries. It reads `.node-version` and `.nvmrc` files, so projects can specify a Node.js version. Shell setup can also enable automatic version switching when changing directories. The project provides setup instructions for Bash, Zsh, Fish, PowerShell, Windows Command Prompt, and Cmder. Its binary includes completions for Bash, Zsh, Fish, and PowerShell. On macOS and Linux, the installation script requires `curl` and `unzip`. The repository identifies the license as GPL-3.0 and invites pull requests, with issues available for project interaction. No paid plans are listed. The project page reports no published security advisories, while also noting that it has not set up a SECURITY.md file.

Jabba is a free Java version manager written in Go for installing and switching among JDK versions on macOS, Linux and Windows. Its JDK index, powered by DiscoAPI, lists versions for the user's operating system and architecture. The README names distributions including Oracle, Adopt OpenJDK, Zulu, IBM SDK, GraalVM, OpenJDK, Liberica and Amazon Corretto. Users can list remote JDKs, filter versions with semantic version ranges, install versions and switch among those installed. A `.jabbarc` file can specify a project's JDK, while a default alias can select the version used in new terminals. Jabba can link to a system JDK and coexist with an existing Java installation. The README documents shell integration for bash, zsh and fish, plus installation through Homebrew, shell scripts, PowerShell, Scoop or Docker. Custom JDK downloads are also supported. Jabba does not switch Java globally on its own; the README gives manual platform-specific snippets instead. The repository describes Jabba as a community fork that is a work in progress and warns that some README instructions may be outdated. It is licensed under Apache-2.0.