JavaScript knowledge is essential for working with today’s Web, whether you’re building applications for the client, the server, or for mobile use—and your PHP experience gives you a head start. This book will help you become fluent with JavaScript quickly, and then serve as a handy reference once you start coding.
Stoyan Stefanov (http://phpied.com, @stoyanstefanov) is a Facebook engineer. Previously at Yahoo! he was the creator of the smush.it online image optimization tool and architect of YSlow 2.0. performance tool. Book author (JavaScript Patterns, Object-Oriented JavaScript), contributor (Even Faster Web Sites, High-Performance JavaScript) and speaker (Velocity, JSConf, Fronteers, Ajax Experience).