chruby vs rustup

chruby is a free, MIT-licensed shell utility for changing the Ruby version used in a session. Selecting a Ruby updates PATH and sets GEM_HOME and GEM_PATH for that installation. It can match installed Ruby names fuzzily and uses the system Ruby when no selection is made. Optional automatic switching checks the current and parent directories for a .ruby-version file. chruby supports bash 3 or later and zsh on Linux and macOS. Installation instructions cover a release tarball, Homebrew, Arch Linux AUR, Fedora Copr, and FreeBSD ports. Additional Ruby implementations can be installed with ruby-install or ruby-build. The project provides guidance for integrations including Capistrano, Chef, Cron, Emacs, Pow, Puppet, Sudo, Vim, and Fish. Releases are PGP signed, with verification instructions, and the codebase is described as about 100 lines with tests.

rustup installs Rust from its official release channels and manages the toolchains and supporting components developers use. It can switch among stable, beta, and nightly compilers, keep toolchains updated, and install specific versions or dated releases. For cross-compilation, add a target’s standard library with `rustup target add`; Android builds also require the Android NDK and usually a linker. rustup manages official channels, archived releases, alternate hosts, and local builds. It installs command proxies for tools including rustc, rustdoc, Cargo, rust-analyzer, Clippy, and Miri. Component availability varies by release and toolchain, especially for nightly. Installation uses a shell script on Unix and rustup-init.exe on Windows. Downloads use HTTPS, but download signatures are not yet validated. rustup is free and open source, with a free plan. Its listed supported platforms are Linux, macOS, and Windows; the installer also runs on FreeBSD, NetBSD, Solaris, and illumos.