At the time of writing, we are using IntelliJ version 15.x or later (for example, version 2016.2.4) to test the examples in the book, but feel free to download the latest version. Once the installation file is downloaded, double-click on the downloaded file (.exe) and begin to install the IDE. Leave all the installation options at the default settings if you do not want to make any changes. Follow the on-screen instructions to complete the installation: