You will need a machine that is capable of running Node.js. We will discuss how to install this in the first chapter. You can run it on pretty much anything, but having a few extra gigabytes of RAM available will probably help while developing. Some of the mapping examples later in the book are kind of CPU-intensive, though most machines produced since 2014 should be able to handle them.
You will also need the latest version of your favorite web browser; mine is Chrome, and I use it in the examples, but Firefox also works well. You can try to work in Safari, Internet Explorer/Edge, Opera, or any other browser, but I feel that Chrome's Developer Tools are the best.