This is just one of those books every Flex developer should own. With each release, Flex has continued to prove its pedigree as the best framework for developing rich interactive experiences. Flex 4 is no exception (it is a superb example of how an ECMA based language and XML can be combined into a stellar programming environment). It has been overhauled with features that make creating apps an absolute joy; it's as if the developers of the Flex framework personally listened to the community's feedback and integrated the best suggestions. The authors of this book are extremely well respected Flex developers and active community participants, so it's no wonder they produced a book that covers every important detail each new or seasoned developer should know. I've been stuck on numerous occasions, whereby turning to the cookbook solved my problems so that I could go about my day without losing any hair. This book covers all of the new features like skinning, states, the spark component framework, layout management, animation and Air 2.0 as well as covering features from the previous versions. All in all, if you are new to Flex or just need a tip or two (or thirty), this book is well worth the money and won't let you down.