This book can be read without a computer or laptop to hand; you need nothing more than the book itself. However, to follow the examples in the book, you need Java 8, which you can download from http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html, and you will also need your favorite IDE for the examples. I have used the Spring Tool Suite (STS). Download the latest version of STS from https://spring.io/tools/sts/all according to your OS. Java 8 and STS work on a variety of platforms, including Windows, macOS, and Linux.