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 Mastering Regular Expressions, Second Edition, are owls. There are two families and approximately 180 species of these birds of prey distributed throughout the world, with the exception of Antarctica. Most species of owls are nocturnal hunters, feeding entirely on live animals, ranging in size from insects to hares.

Because they have little ability to move their large, forward-facing eyes, owls must move their entire heads in order to look around. They can rotate their heads up to 270 degrees, and some can turn their heads completely upside down. Among the physical adaptations that enhance owls' effectiveness as hunters is their extreme sensitivity to the frequency and direction of sounds. Many species of owl have asymmetrical ear placement, which enables them to more easily locate their prey in dim or dark light. Once they've pinpointed the location, the owl's soft feathers allow them to fly noiselessly and thus to surprise their prey.

While people have traditionally anthropomorphized birds of prey as evil and coldblooded creatures, owls are viewed differently in human mythology. Perhaps because their large eyes give them the appearance of intellectual depth, owls have been portrayed in folklore through the ages as wise creatures.

Jeffrey E. F. Friedl was the production editor for Mastering Regular Expressions, Second Edition. Sarah Jane Shangraw was the proofreader. Jane Ellin provided quality control.

Edie Freedman designed the cover of this book. The cover image is a 19th-century engraving from the Dover Pictorial Archive. Emma Colby produced the cover layout with QuarkXPress 4.1 using Adobe's ITC Garamond font.

The text was prepared by Jeffrey Friedl in a hybrid markup of his own design, mixing SGML, raw troff, raw PostScript, and his own markup. A home-grown filter translated the latter to the other, lower-level markups, the result of which was processed by a locally-modified version of O'Reilly's SGML tools. That result was then processed by a locally-modified version of James Clark's gtroff, producing camera-ready PostScript for O'Reilly.

Ken Lunde of Adobe Systems provided special font and typesetting help, including custom-designed characters and Japanese characters from Adobe Systems's Heisei Mincho W3 typeface.

The text and heading fonts are ITC Garamond Light and Garamond Book; the code font is Constant Willison. The illustrations that appear in the book were produced by Chris Reilly, Robert Romano, and Jessamyn Read using Macromedia FreeHand 9 and Adobe Photoshop 6.