asdf is a tool version manager. All tool version definitions are
contained within one file (.tool-versions) which you can check in to
your project's Git repository to share with your team, ensuring everyone
is using the exact same versions of tools.

The old way of working required multiple CLI version managers, each with
their distinct API, configurations files and implementation (e.g. $PATH
manipulation, shims, environment variables, etc...). asdf provides a
single interface and configuration file to simplify development
workflows, and can be extended to all tools and runtimes via a simple
plugin interface.