In memory of all the victims of the attacks on September 11, 2001 Table of Contents PrefaceWho You AreWhat You Need to KnowWhat You Need to HaveHow to Use This BookThe Online EditionSome grammatical notesContacting the AuthorAcknowledgements1. XML for DataMotivating XMLA Thought ExperimentRobustnessExtensibilityEase of UseXML SyntaxXML DocumentsXML ApplicationsElements and TagsTextAttributesXML De