THIS IS THE FIFTH EDITION OF A BOOK that has proven popular with professional developers and academic institutions. It strives to impart knowledge on a subject that at fi rst was seen by some as just another fad, but that instead has come to maturity and is now often just taken for granted. Almost six years have passed since the previous edition — a veritable lifetime in IT terms. In reviewing the fourth edition for what should be kept, what should be updated, and what new material was needed, the current authors found that about three-quarters of the material was substantially out of date. XML has.
