Sometimes you may want to have more than one version of Elm installed on your computer.
It could be that you're in the process of upgrading multiple projects, and you'd like to have one in 0.18 and another in 0.19. It could be you want to pin your version of Elm to something specific so you can be sure all the members of your team are using the same one. It could be you're relying on lots of Elm-related tooling, and you want to make sure you have the right combination for a specific project.
One option is to piggy-back on top of the [Node Package Manager][npm], and explicitly declare which version of Elm you'd like to use. The
elm binary is wrapped up as a node module with a bit of metadata:
$ npm info elm@latest email@example.com | BSD-3-Clause | deps: 1 | versions: 33