Parsoid/Installing Node

Nodejs
Install nodejs >= v4.x and the node package manager, npm. After installing, type node --version and it should print

If you are on Ubuntu or Debian, you can use apt-get to install these packages. (However, depending on OS version you will not end up with the most recent version of nodejs. Please read this before you proceed.)

For other systems, see:
 * https://nodejs.org/en/download/
 * https://nodejs.org/en/download/package-manager/

You can also use a virtual environment like nvm or nave, which lets you install different node versions as a normal user (not system-wide as root) and easily switch between them.