IBM have released XML
Schema Quality Checker, a Java application which finds errors in schemas
utilizing the W3C XML Schema Recommendation syntax.
Part of the alphaWorks site, the code is available for evaluation and
potential licensing.
Where possible the schema checker suggests fixes where appropriate, and can
also be run in batch mode to process multiple schemas in one invocation.
Umm... isn't this what we've got an XML Schema language *for*? Or maybe there is a need for (yet) another schema language that could do this kind of extra-fancy syntactic validation...?