This ouvert my eyes about JavaScript. This is not a book for beginner program. If you know a language like Scheme / Haskell, Then You will learn how to write in JavaScript Correctly. I first thought something like JavaScript, VBScript Was with a Java syntax. Aim this book Explained to me how to use JavaScript the right way. I started to look at JavaScript When I saw demonstration Some of the language, like GUI, Cryptographic operations. Current browsers are really very efficient using JavaScript. It is a full language and usable solution to write programs in the browser. Thank you Douglas Crockford.