I would first like to thank Brian Jepson, who conceived the book and was generous enough to invite me to participate in its development. I would like to express my gratitude to both Brian and Chuck Toporek for their encouragement, patience, stimulating discussions, and kindness. Thanks to Leon Towns-von Stauber for contributing Appendix B to this book. I am also grateful to reviewers for useful suggestions and insights, to visionary folks at Apple Computer for producing and constantly improving Mac OS X, and to developers who spend a great deal of time writing applications and posting helpful insights on newsgroups, mailing lists, and web sites. Finally, I am very grateful to my lovely wife, Kim, for her love, patience, and encouragement, and to my Newfoundland dogs, Max and Joe, for their unconditional love and affection.