Michael Fitzgerald is Principal at Overdue Books LLC, a publishing and writing firm. He is the author of Learning Ruby, Ruby Pocket Reference, XML Pocket Reference, Third Edition with Simon St. Laurent, XML Hacks, and Learning XSLT, all published by O'Reilly. He is also the author of Building B2B Applications with XML: A Resource Guide and XSL Essentials (both by John Wiley & Sons). His books have been translated into Spanish, French, German, Japanese, and Chinese. He has also been a regular contributor to XML.com. Michael likes to ski (downhill and cross country), ride and train horses, and spend time with his family.