The 2015 specification for the JavaScript language introduces classes, modules, arrow functions, and more. I sat down and wrote the book I would like to read about these new features. This book is not an exhaustive list of everything new in the ECMAScript 2015 specification that governs the JavaScript language. Instead, I purposefully selected what I think are the important features we will use in everyday programming. I expect the reader will already have a good understanding of the JavaScript language as the language existed before 2015.