XML

[ This page has benefitted from some recent drastic pruning! As well, it doesn't pretend to be much more than a set of roughly ordered bookmarks for me. For a truly compendious resource, see the Cover pages ]

XML is an application profile or restricted form of SGML. See a thread on this topic in comp.text.xml.

Sources

• The W3C's The XML pages. The XML Activity pages summarise what's going on at present.
• XML spec (Second Edition) consists of the original XML spec plus the errata from the first edition.
• XML is a subset of SGML, which removes some of SGML's features and options, and hence some of its overwhelming flexibility (see appendix C of the spec, which refers to a longer discussion in a W3C note from James Clark). Crucially, however, XML retains SGML's extensibility, and does not have HTML's crippling restriction to a single set of markup elements to describe an infinite variety of documents.
• The XML Cover Pages, Robin Cover's magnificent compendium of everything to do with SGML and XML, includes a collection of introductions to XML
• XML in 10 points
• See also the annotated spec and Goldfarb's annotated list of XML books in print.
• XML FAQ
• Zvon is a large collection of documentary resources mostly, but not exclusively, on XML.
• Namespaces - central to XML. The Namespaces in XML spec is quite readable (I think), and James Clark's alternative explanation is terse (as usual) and clear (likewise). Ronald Bourret's Namespaces FAQ. The length of this FAQ would give you the impression that namespaces are terribly hard. They're not: they represent a simple idea with some slightly (probably inevitably) awkward syntax. See Why are XML namespaces so hard to understand and use? in the FAQ (the answer there is they're not), and Namespace Myths Exploded for an account of what all the fuss was about, back when namespaces were new (the myths in that document seem to me to result from folk either misunderstanding or massively overinterpreting the spec).

Contents

• Associated standards
  [XSL; Linking; XQuery; XML Schema; MathML; Data models; RDF and the Semantic Web]
• APIs and application support
• Other resources