*Standard*: http://www.oasis-open.org/committees/relax-ng/ RelaxNG is a SchemaLanguageForXML based on RegularTreeGrammars. It is (suprisingly) more powerful and easier to use and learn than XMLSchema. The RelaxNG standard inclused a well-defined formal semantics. There is also a (currently not standardized) [[http://www.thaiopensource.com/relaxng/compact/index.html][concrete syntax]] in addition to the standard XML syntax. Jing is the RelaxNG validator of JamesClark: http://www.thaiopensource.com/relaxng/jing.html -- Main.MartinBravenboer - 30 May 2002