I am deeply indebted to Michael Kay, not only for his detailed review of this book, but also for his excellent Saxon XQuery implementation, without which I would not have been able to reliably test the examples.

Ron Bourret, Bob DuCharme, Tim Finney, Ashok Malhotra, Darin McBeath, Peter Meggitt, Shannon Shiflett, and Bruno J. Walmsley (my father) provided extremely helpful comments on, and assistance with, this book.

This project would not have been possible without Simon St.Laurent, who provided editorial guidance and championed the book within O'Reilly. Thanks, Simon!

Finally, I would like to thank Doug, my partner, my love, for his constant support and encouragement during the busy years I have spent writing this book.