If you are arriving at AJAX with a basic web development foundation, you will find "Ajax in Action" to be challenging to digest. From the introduction, the overall level of the book jumps right into code samples and skips most of the basics, making it an intermediate book at best.I found the chapter on Ajax portal architecture using Java to be particularly useful, along with the Live Search chapter. But besides that, I didn't find as accessible as another book titled "Foundations of Ajax". I would recommend "Ajax in Action" only to developers who have at least a couple of years of web dev under their belt.