说明：  This book is for anyone who wants to understand Symbian OS bet- ter – what Symbian OS is, why it is what it is, and how it got to be that way. If you work with Symbian OS, or intend to, this book is for you. If you want to get under the skin of the OS and understand it more deeply, this book is very defi nitely for you. This book is for you too if you are interested in the software or mobile phone industries more generally, or in the perennial themes of software development, or are merely curious about how real systems get made and evolve. A reasonable degree of software technical literacy is assumed, but not so much that the more casual reader should shy away. There are no exercises. And there is no sample code.