XML in A Nutshell 2nd Edition from O'Reilly Press and authored by Rusty Harold and Scott Means does not a mean job of walking the tightrope between to much and too little about the various XML dialects. the authors start out by desriing with graduated examples real XML data sets, then DTDs (descriptors of the XML datasets), then XSchemas (database level descriptors) and finally and excursion into namespaces (how to safely name XML tags and attributes).

Having covered the fundamentals with well chosen examples, the authors divide XML standards into Narrative-centric (think word processing and DTP documents) and data centric(think database records and objects). What the authors imply but don't explicitly state is a third category - Program-centric messages and calls which makes up the big XML SOAP and Web Services arena which is not covered in the book. But the authors do an admirable job of covering Narrative-centric standards such as XSLT-XML StyleShett Transformations, XPath and XLinks for enhanced linking capabilities, plus CSS_cascading StyleSheets and XSLFO-XSL Formating Objects used to style and format XML documents for printing, presentations and reports. The Data-centric chapters discuss programming XML in Java, C, etc using DOM-Document Object Model and SAX-Simple API for XML approaches. Rapidly evolving XForms and XQuery and all Web Services are just mentioned briefly. But don't be fooled, this nutshell covers an awful lot of XML very concisely.