- It is used everywhere on the internet: with different browsers and in different versions
This is some start, but when you hit real projects, they are often written with ECMA Script6 and let me tell you the difference is huge.
Browns book starts with a complete set up for your project. You are told how to write ECMA Script 6 and how to back translate it into ECMA Script 5. This is a great approach and as far as I can tell many successful projects today work that way.
It teaches you ECMA Script 6.