Diffing XML Schemas

[Steve Garcia]

I would like to use Torque to generate our SQL from an XML schema.  One of
our requirements is to upgrade existing schemas to the current schema
definition.  Does Torque have any tools to diff two Torque XML Schemas and
produce the resulting upgrade SQL script?  If not, are there other tools
that you know of that can help do this?  
 
Thank you very much, Steve