All the tools that we will use are written in JavaScript. A long time ago, the only way to execute JavaScript was to use a browser, but those days are long gone. Nowadays, we can execute our development tools from the command line during our normal development cycle or from a Continuous Integration (CI) server whenever we commit our changes to a source code repository.
The most easy and productive way to run our test tools is to use Node. Node is a lightweight and highly-scalable platform for JavaScript, written on top of the excellent V8 JavaScript virtual machine. Node is especially good for applications that perform high-volume IO, but it can also be used as a development platform, as we will see in a moment.