RELAX NG An ISO Standard
On December 1, 2003, RELAX NG was published by ISO as an international standard ISO/IEC 19757-2:2003.
- James Clark's post to relaxng-user
- ISO's RELAX NG page
- The text of the standard
For those who don't know, RELAX NG is an XML schema language that is reasonably designed and extremely easy to use (compare with the W3C XML Schema Language).