On Mon, May 12, 2008 at 2:24 PM, Costello, Roger L. <costello@m...> wrote:
> > I wonder how many users are actually eager to learn more
>  > than one schema language, and willing to do so for the
>  > benefits one language has over another.
>
>  I know multiple "programming" languages.  Each have their niche.
>
>  Similarly, each of the "schema" languages - XML Schema, Relax NG, DTD,
>  Schematron - have their niche.
>
>  That said, "learning multiple schema languages" is a red herring.  The
>  fact is, people do use different schema languages, for whatever reason.
>  NVDL gives us the ability the abstract away from the particular schema
>  language being used and focus of utilizing the XML vocabularies
>  provided by the schemas.  That, in my opinion, is powerful ... and what
>  makes NVDL a disruptive technology.

I have always thought that the situation we have where no dominant
schema language is probably a good thing over time, instead of a
single general solution we let domain specific schema technologies
(DSC, like DSL but little languages and toolsets for schemas) emerge
... as long as the cost of using these little domain schema languages
is not high then why not (esp if there is an NVDL to facilitate)

u make a good characterisation of NVDL power ... I used to agree with
the 'more is better' mantra; but this goes away when u find out that
there can be situations where 2 schema technologies disagree on
validity and it becomes very hard to do a 'union' of the assertions
that they both positively make .... and who knows what to make of the
negative assertions (usually a manual process).

cheers, Jim Fuller