A jarfile, so you don't need to include it in your repository
npm install selenium-server-standalone-jarThis repository includes a jarfile. It points to it.
npm install --save-dev selenium-server-standalone-jar
This is up to you. All you get is:
var jar = require('selenium-server-standalone-jar');
console.log(jar.path); // path to selenium-server-standalone-X.YY.Z.jar
console.log(jar.version); // X.YY.Z
This repository has no advice as to how to run the jar. Other libraries should
fill that void; they can depend on this library to keep things simple.