RVM has long been an essential tool in the Rubyist’s toolbox. It was a huge leap forwards, but it has been increasingly falling out of favour. Recently, a large chunk of the Ruby community moved to rbenv. Touted as the nimble successor to RVM, rbenv has a much leaner feature set, and takes a rather different approach to managing multiple Ruby versions. Whereas RVM would override shell builtins such as cd, rbenv provides shims - small executables that select the correct Ruby version when run.