Elm is a functional programming language that compiles to JavaScript.
Head over to The Official Guide to start learning Elm!
For normal installs, I reccomend using the instructions here instead. This package is only for people who enjoy using npm even when it is not necessary, or for people who want to use npm for certain scenarios such as:
Multiple versions
People using Elm at work may use different versions of Elm in different projects. They can run npm install elm@latest-0.19.2 in each project and use the binary at