To put a final piece on this jigsaw, I would also note that if you want to generate schema-to-schema stylesheets, especially for complex formats like MARCXML, in a user-friendly way, you could do worse than MINT:
I am currently working with the developers of MINT and I'm happy to put you in touch.
You might need some developer resource to implement a MARC21 instance, but there may be one out there and/or the newer open source release may allow you to specify source schema directly.
I can't imagine that the need to map from X to MARC21 is that uncommon... probably why there's also http://www.extensiblecatalog.org/
> On Mon, Nov 5, 2012 at 2:15 PM, john passmore <[log in to unmask]>
> > Hi,
> > Before I start reinventing the wheel, does anyone know of any
> > stylesheets out there that convert PBCore 2.0 XML
> > <http://pbcore.org> to MARC XML<http://www.loc.gov/standards/marcxml/>?
> > Thanks!
> > John
> > WNYC Archives