Development of XML and its related standards, specifications, and vocabularies is proceeding at an almost explosive rate, with simultaneous progress on many fronts and with ever-evolving objectives. Those who want or need to learn about XML quickly need answers to questions like these: What is XML? Where did it come from? How do I get started? What do I concentrate on? What can I learn that’s useful to me now? How long is it going to take to be productive with XML? With this book we can help to answer those questions.