rubyenv

Version manager for Ruby on Unix-like systems that lets you switch between multiple Ruby versions on the same machine and ensures each project runs on the correct version. Uses a lightweight shim-based design that intercepts ruby, gem, bundle, and related executables without modifying the system Ruby.

rbenv follows a minimal, do-one-thing-well philosophy compared to alternatives like RVM. Version selection is driven by a .ruby-version file in each project directory, so teams can commit the required Ruby version and new developers get the right version automatically. The project has been the default recommendation in Ruby’s official installation docs and ships in Homebrew, apt, pacman, dnf, and zypper.

Key capabilities:

• Per-project version selection via .ruby-version with automatic switching when changing directories
• Global and shell-specific overrides for defaults and one-off runs
• Plugin-based design, with ruby-build for compiling and installing Ruby versions
• Shim-based execution that routes commands to the appropriate Ruby installation
• Supports MRI, JRuby, Rubinius, and REE through the same interface

Teams use rbenv to pin Ruby versions per app, test against upcoming releases, and keep CI and local environments aligned. Integrates with existing Ruby tooling: ruby, gem, bundle, and other executables all resolve through rbenv when enabled.