Eric van der Vlist announced XML Validation Interoperability Framework (XVIF): a proposal for embedding processing pipeline definitions into XML schema languages, particularly RELAX NG. He has also developed a RELAX NG implementation with XVIF features in Python, and an on-line demo running this implementation.

Eric van der Vlist is editor of DSDL Part 1 - Interoperability Framework, but his proposal, detailed in this document, doesn't carry any official status in DSDL. He does hope that it will help jumpstart discussion by demonstrating how such a schema interoperability framework could work in practice. There is also a mailing list for XML schema diversity and interoperability.

The open source Python implementation supports most RELAX NG features, excepting support for references to external grammars and pluggable data types. It also adds XSLT, XPath and regular fragmentations processing steps.

Recent, related stories:

• XML and the IETF: Making the case for RELAX NG
• RELAX NG gets "feasible validation" support
• Topologi schema validator adds RELAX-NG support (3 items down)