JavaScript runtime

In order to execute TypeScript and many other tools in the JavaScript ecosystem, you'll need a JavaScript runtime. The default option here is Node.js (https://nodejs.org).

Node.js provides multiple things when you install it:

• A JavaScript runtime available via the node command-line interface: https://nodejs.org/api/cli.html
• An SDK: https://nodejs.org/en/docs
• A package manager called npm—see next point for details

Node.js can actually be used to develop full-blown applications, but in this book, we will mainly use its runtime and package manager. We will only use the Node SDK indirectly.

For the purposes of this book, though, the necessary knowledge of Node.js will be quite limited, as you'll see shortly.