Acknowledgments

A special thanks to my friends and colleagues at Valtech, world-class iterative developers, especially Tim Snyder.

Many thanks to the reviewers, including Alistair Cockburn, Claudia Frers, Tom Gilb, Jim Highsmith, Ron Jeffries, Philippe Kruchten, Niels Maloteaux, Gary Pollice, Ken Schwaber, and Jeff Sutherland.

Thanks to Paul Petralia and Patti Guerrieri for shepherding.