Welcome to the exciting world of XML! This book is by an old guy and four young guys. The old guy (HMD; Massachusetts Institute of Technology 1967) has been programming and/or teaching programming for 40 years. The four young guys (PJD; MIT 1991, TRN; MIT 1992, TML; Carnegie Mellon 2001, PS; Northeastern 2000) have each been programming and/or teaching programming for many years. The old guy programs and teaches from experience; the young guys do so from an inexhaustible reserve of energy. The old guy wants clarity; the young guys want performance. The old guy seeks elegance and beauty; the young guys want results. We got together to produce a book we hope you will find informative, challenging and entertaining. Why We Wrote XML How to Program

Today, XML is arguably the hottest technology in the computer industry. Therefore, university professors are eager to incorporate XML into their undergraduate and graduate Internet, Web, e-business and e-commerce curricula. Professionals are eager to use XML in their industrial-strength information-technology applications. Students are highly motivated by the fact that they are learning a leading-edge technology (XML) that will be immediately useful to them as they leave the university environment and head into a world where the Internet and World Wide Web have a massive prominence.