Hi -

Does anyone know of a shareware/freeware or commercial system that would
allow me to retrieve resources such as DTDs, external entities, namespaces,
and stylesheets across a network by using their system identifier (or
perhaps their public identifier, in the case of public DTDs) as a generic
resource identifier rather than an explicit resource identifier?  I'm
trying to find a way to do versioning on these resources without having to
change the documents I've created, and I want to be able to take the SI for
these resources and transparently convert it to the "real" resource name.
I've seen the SYSTEM catalog entry in the SGML Entity Management document
(TR 9401:1997), and I've seen the "remap" feature in John Cowan's XML
Catalogs proposal, but I have yet to find a product that does what these
documents describe across a network rather than using local catalogs.  I
*could* just rename my current version (and the previous versions I have
laying around) and then put the new one at the well-known URI, but if at
all possible I'd rather just change some name-resolution mechanism to point
to a new resource (and besides - at some point I might be pointing at
resources that aren't mine).

Is this a reasonable thing to do?  If so, how can I do it?


 "Be very, very careful what you put into that head, because you will
never, ever get it out."

- Thomas Cardinal Wolsey (1471-1530)