rbenv is a Ruby version manager and shell environment manager designed to install, switch between, and manage multiple versions of the Ruby programming language. It functions as a project runtime isolator and an extensible versioning framework that ensures the correct Ruby binaries are executed based on the current context.
The system uses a shim-based command interception model to resolve the active version before delegating execution to the binary. It allows for locking specific Ruby versions and environment variables to individual directories, ensuring project environment isolation. The architecture is designed for extensibility, allowing users to add custom commands and hooks through a plugin system.
The tool covers a broad range of capabilities including version management, toolchain configuration, and the management of environment variables. It provides mechanisms to automate library setup and isolate dependencies across different installations.