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 animals on the cover of Enterprise JavaBeans, Fourth Edition, are a wallaby and her joey. Wallabies are middle-sized marsupials belonging to the kangaroo family (Macropodidae, the second-largest marsupial family). They are grazers and browsers, native to Australia and found in a variety of habitats on that continent. Female wallabies have a well-developed anterior pouch in which they hold their young. When they are born, the tiny, still-blind joeys instinctively crawl up into their mothers' pouches and begin to nurse. They stay in the pouch until they are fairly well-grown. A female wallaby can support joeys from up to three litters at once: one in her uterus, one in her pouch, and one that has graduated from the pouch but still returns to nurse.

Like all Macropodidae, wallabies have long, narrow hind feet and powerful hind limbs. Their long, heavy tails are used primarily for balance and stability and are not prehensile. Wallabies resemble kangaroos, but are smaller: they can measure anywhere from less than two feet to over five feet long, with the tail accounting for nearly half of their total length. Oddly enough, although they can hop along quite quickly (reaching speeds of up to 50 km/h), it is physically impossible for wallabies to walk backward!

The three main types of wallaby are brush, rock, and nail-tailed. There are 11 species of brush wallaby (genus Macropus), including the red-necked and pretty-faced wallabies, and 6 named species of rock wallaby (Petrogale). Brush wallabies usually live in brushland or open woods. Rock wallabies, which are notable for their extreme agility, are usually found among rocks and near water. There are only three species of nail-tailed wallaby (Onychogalea), which are so named because of the horny growth that appears on the tip of their tails. Two of these species are endangered--although they were once the most numerous type of wallaby, their numbers have been seriously depleted by foxes and feral cats. Aside from hunting and habitat destruction, predation and competition by introduced species such as these are what threaten wallabies today. Colleen Gorman was the production editor and copyeditor for Enterprise JavaBeans, Fourth Edition. Leanne Soylemez was the proofreader. Reg Aubry and Mary Anne Weeks Mayo provided quality control. Julie Hawks wrote the index.

Hanna Dyer designed the cover of this book, based on a series design by Edie Freedman. The cover image is an original engraving from The Illustrated Natural History: Mammalia, by J.G. Wood, published in 1865. Emma Colby produced the cover layout with QuarkXPress 4.1 using Adobe's ITC Garamond font.

David Futato designed the interior layout. This book was converted by Julie Hawks to FrameMaker 5.5.6 with a format conversion tool created by Erik Ray, Jason McIntosh, Neil Walls, and Mike Sierra that uses Perl and XML technologies. The text font is Linotype Birka; the heading font is Adobe Myriad Condensed; and the code font is LucasFont's TheSans Mono Condensed. The illustrations that appear in the book were produced by Robert Romano and Jessamyn Read using Macromedia FreeHand 9 and Adobe Photoshop 6. The tip and warning icons were drawn by Christopher Bing. This colophon was written by Rachel Wheeler.

Whenever possible, our books use a durable and flexible lay-flat binding. If the pagecount exceeds this binding's limit Perfect Binding is used.