First of all, thanks to my husband, David North. Not only did he help enormously with formatting, proofreading, finding sample photos, and endless testing of GIMP quirks on multiple platforms, but he also put up with the neuroses of a stressed-out first-time author. And then he was willing to do it all again for a second edition!

Equally important is Guillermo Romero, the book's technical reviewer, without whom this book would not have been possible. He patiently waded through first drafts, flagged my silly errors, asked probing questions, and took the time to teach me a lot about digital art. I'm not an artist yet, but I'm learning.

Thanks to Pat Peck (hi, Mom!) and the members of Linuxchix who were willing to be guinea pigs for the online GIMP course that indirectly led to this book. And to two other Linuxchix: Carla Schroder, for all her encouragement, writing tips, and witty remarks; and Dana Sibera, for laughs, explanations of techniques, and an appreciation of what a real artist can do with (or to) a photo.

Thanks to all the GIMP developers for using their talents and spare time to create such a wonderful program, and for spending even more time explaining details of the program to folks who need help. Some of the most active: Sven Neumann, Michael Natterer, Bill Skaggs, Martin Nordholts, Øvind Kolås, Kevin Cozens, João S. O. Bueno, Alexia Death, Michael Schumacher, Mukund Sivaraman, Ulf-D. Ehlert, Simon Budig, Tor Lillqvist, Manish Singh, Karine Delvare, David Odin, and Maurits Rijk.

Thanks to Lisa and Evan Avery, for letting me use the photo of their son Ethan; to Cathleen Wang Blythe and Polarbear; to Bill Condrashoff, Benita Asher, and Jackpot; and to Dave Nakamoto and Dragan Stanojević- Nevidljivi for helping out with samples of image stacking (which unfortunately didn't make it into the final version due to space considerations).

Last but not least, many thanks to the folks at Apress for helping me through every step of the process, and for putting up with all my tweaks and revisions. In particular, thanks to open source editor Matt Wade, project manager Beth Christmas, awesome copy editor Liz Welch, production editor Jill Ellis, and proofreader April Eddy.