Henry S. Thompson has announced the release of a web interface, Windows binary self-installer, and Python source code for a new version of the open-source W3C XML Schema validator XSV that implements a "cheap-but-effective approximation to enforcement of the constraints on derivation by restriction for complex type definitions".

Thompson notes that though the implementation falls short of full conformance, it will "go a lot further towards enforcing interoperability between XSV and other processors which do enforce the REC as intended".