Evan Lenz is an application developer whose primary expertise is in XSLT. As a member of the W3C XSL Working Group, he has been contributing to the development of XPath 2.0, XSLT 2.0, and XQuery 1.0. He has spoken at various XML conferences and helped author books including Wrox's ""Professional XML, 2nd Edition"", and ""Early Adopter XQuery"" (foreword). Evan holds a Bachelor of Music degree from Wheaton College, with majors in Piano Performance and Philosophy. He currently lives in Seattle, Washington, with his wife Lisa and son Samuel. Website: http://www.xmlportfolio.com.Simon St. Laurent is a web developer, network administrator, computer book author, and XML troublemaker living in Ithaca, NY. His books include XML: A Primer, XML Elements of Style, Building XML Applications, Cookies, and Sharing Bandwidth. He is a contributing editor to XMLhack.com and an occasional contributor to XML.com.