# JavaScript Prototype Fun > [https://youtu.be/WJWkqf_N3Sg](https://youtu.be/WJWkqf_N3Sg) Install [io.js](https://iojs.org/en/index.html). Within this folder run the terminal command `npm install` to install the `devDependencies`. Then run `npm start` to start up a development server on `http://localhost:9966`