frum vs Jabba

frum is a free Ruby version manager written in Rust. It can install and uninstall Ruby versions, list available or installed versions, and select a global or local version. It also works with .ruby-version files, so projects can specify which Ruby version frum should use. The project describes its implementation as pure Rust and says it does not use ruby-build. Installation methods listed include Homebrew or Linuxbrew, Arch Linux packages, Cargo, and release binaries. The README provides setup instructions for Bash, Zsh, and Fish and lists shell auto-completion. Ruby installation accepts configuration options such as an OpenSSL directory and jemalloc allocator selection. The README reports a benchmark in which evaluating frum init ran about six times faster than evaluating rbenv init. The project is MIT licensed and welcomes contributions, issues, and pull requests. Linux and macOS are listed as supported platforms; Windows is mentioned in the project’s goals. Its latest listed release is v0.1.2.

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describes Jabba as a community fork that is a work in progress and warns that some README instructions may be outdated.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.