The PNG Guide is an eBook based on Greg Roelofs' book, originally published by O'Reilly.


Our look is the result of reader comments, our own experimentation, and feedback from distribution channels. Distinctive covers complement our distinctive approach to technical topics, breathing personality and life into potentially dry subjects.

The animal on the cover of PNG: The Definitive Guide is a kangaroo rat. There are about 20 species of kangaroo rat (genus Dipodomys, family Heteromyidae) found in western North America. Some of these species are endangered. These small mammals are equipped with long, narrow feet that enable them to get about with long, strong hops. They can travel as far as two meters per hop. Their tufted tails, which are approximately as long as their bodies, are used as rudders. The forearms of kangaroo rats are so short that they often disappear within their fur. Most kangaroo rats have a color similar to the sand or soil of their environment, with black or white facial markings and two stripes running down the back. Albino kangaroo rats do occasionally appear. Like all of their relatives in the Heteromyidae family, kangaroo rats have large, fur-lined pouches in their cheeks into which they stuff food to carry back to their nests. They eat grass, plant greenery, and seeds. It is not uncommon to find evidence of a visit by a kangaroo rat in vegetable gardens. Remarkably, they are able to obtain all the water they need from the food that they eat. Kangaroo rats are able to live their entire lives without ever drinking water.

Kangaroo rats are nocturnal animals. They tend to be antisocial and belligerent. Kangaroo rat fights frequently occur. During these fights they jump in the air and kick at each other with their powerful legs. Kicking, in this case kicking sand, also comes in handy when cornered by enemies such as rattlesnakes or coyotes. While the enemy has sand in its eyes, the kangaroo rat makes his hopping getaway.

Kangaroo rats build their subterranean nests beneath small bushes or trees. They line the nests with leaves or grass, and build in numerous tunnels and escape outlets.

Nancy Kotary was the production editor and copyeditor for PNG: The Definitive Guide; Norma Emory was the copyeditor; Madeleine Newell was the proofreader; Nicole Gipson Arigo, Jane Ellin, and Sarah Jane Shangraw provided quality control. The illustrations that appear in this book were produced by Robert Romano and Rhon Porter using Macromedia FreeHand 8 and Adobe Photoshop 5. The color insert was designed by Alicia Cech. Seth Maislin wrote the index.

Edie Freedman designed the cover of this book, using a 19th-century engraving from the Dover Pictorial Archive. The cover layout was produced with QuarkXPress 3.32 using the ITC Garamond font.

The inside layout was designed by Nancy Priest and Alicia Cech and implemented in troff by Lenny Muellner. The text and heading fonts are ITC Garamond Light and Garamond Book. This colophon was written by Clairemarie Fisher O'Leary.

About the Author

Greg Roelofs ( is a senior researcher at Philips Electronics, specializing in compression, graphics, 3D, and audio software. He helped design the PNG image format, maintains its official web site, and writes free software in his spare time. Greg holds a doctorate in astrophysics from the University of Chicago.

Last Update: 2010-Nov-26