You are reading the text of an O'Reilly book that's under development. The author is publishing the book to this site as it's being written, and we're putting it here to get feedback from you. This book uses the Open Feedback Publishing System (OFPS), an O'Reilly experiment that tries to bridge the gap between private manuscripts and public blogs.Next to every paragraph, there is a link you can use to comment on what you're reading. We are grateful for any feedback you have: questions, comments, suggestions, and corrections are all welcome and appreciated. Now web designers and developers can join the iPhone app party without having to learn Cocoa's Objective-C programming language. It's true: You can write iPhone apps quickly and efficiently using your existing skills with HTML, CSS, and JavaScript. This book shows you how with lots of detailed examples, step-by-step instructions, and hands-on exercises.