XSV is a command-line tool for performing schema-validity
assessment of XML documents in accord with the
W3C XML Schema specification, second edition.

XSV (XML Schema Validator) is an open source (GPLed) work-in-progress
attempt at a conformant schema-aware processor, as defined by
XML Schema Part 1: Structures, Second Edition of 28 October 2004.
It has been developed at the Language Technology Group of the Human
Communication Research Centre in the School of Informatics at the
University of Edinburgh, with support for one of us (Thompson)
from the World Wide Web Consortium.

WWW: http://www.ltg.ed.ac.uk/~ht/xsv-status.html