Neil Berkman, a software engineer at Bay Networks in Billerica, MA, as well as Andrew Schulman and Terry Allen at O'Reilly were technical reviewers for the Beta edition. Their comments made that edition (and therefore this one) stronger and more accurate. Andrew was also the editor for the Beta edition of this book, and Frank Willison is editor of the current edition. I am grateful to them both.
David Futato was the production manager for this edition of the book and the last. He coordinated the whole process of production, and for the Beta edition, it was he who worked weekends and nights in order to give me time to squeeze the last few new Beta 6 features in. Chris Reilley produced the figures for the book. Edie Freedman designed the cover, and Nancy Priest and Mary Jane Walsh designed the internal format, which was implemented by Lenny Muellner, with help from Erik Ray. Seth Maislin indexed this book.
Finally, my thanks, as always and for so many reasons, to Christie.