I have just released a module that provides an easy way to use Schematron in BaseX. It's is available on GitHub at https://github.com/vincentml/schematron-basex. This module is a convenience wrapper around the standard ISO Schematron XSLTs. 

In addition, a version of this module for eXist-db is available at https://github.com/vincentml/schematron-exist

Vincent

"Everything should be made as simple as possible, but not simpler."