THE MOST IMPORTANT CONTRIBUTION to this book, I must acknowledge, is from the Mac developer community. Thanks, everyone, for showing me that application security does need a champion, and for all your suggestions of topics to cover here and in the Mac Developer Network. Special mention and gratitude must go to Steve "Scotty" Scott for accepting that in lieu of a better option, I could be that champion.
Scott originally suggested that I write a book and James, Sadie and Bill all did a great job of beating my drafts into a publishable state: I'm very grateful to all of them. Of course, I assume full responsibility for any errors that snuck through. Finally, a developer is only as good as the caffeine that fuels him, so particular thanks are due to Freya for her fine supply of coffee and moral support.