open, closed, "SGML for the Web"

["Simon St.Laurent" <simonstl@simonstl.com>]

Recent discussions have left me wondering whether the division in XML
isn't just documents vs. data, relational vs. object, or infoset vs.
lexical.  It seems to me that there is something more at work.

When XML first appeared, it seemed that its creators had at least aimed
to make XML something generically usable over the Web.  With the aid of
XSLT or CSS stylesheets, for example, it's easy to disply content in XML
documents, whatever the vocabulary may be.  XML 1.0 was almost simple
enough to avoid interoperability problems between different parsers, and
pretty much all of the tools worked on any document out there.

Application logic was (and should be) still an issue, but the nature of
the underlying documents was clear.  Elements, attributes, content, and
a few more parts.  DTDs muddied the water a bit, but for the most part
an instance document was plainly a set of labeled structured holding
content.  The nature of the labels (names) and structures (end tags
required) was clear.  We could agree on what a document said, if not
what it meant.

Since then, we've seen all kinds of features added to XML.  We've been
told that we only need to use the features we want to use for our
projects, and that we can run wild with the features we like.

Some place in there, though, the lessons of the Web seem to have been
lost.  What began as "SGML for the Web" seems to be turning into "Markup
for my particular situation which happens to use XYZ toolset with KTM
options turned on/off."  The Web-building idea that information is most
valuable when most accessible, even on a lowest-common denominator basis
seems to have been forgotten by the feature-hungry.

It seems to me that the values which underlie much of the original XML
intiative have been discarded by its successors.  While we now have lots
of new features, we also have tremendous new costs - learning curves,
interoperability issues, software costs, and time spent trying sort out
the implications of these new features.  The new features are as capable
(more capable?) of keeping us from communicating as they are of helping.

I'm not sure that returning to a vision of XML in the context of an open
Web (rather than, for instance, the current Web Services vision of
putting XML and web technology to work in more tightly constrained
conversations) would halt the growth of complexity. It does, however,
seem like a focus on the open Web might at least encourage people to
focus on the few things they have in common, and can solve in common,
rather than the many things which keep them apart.

Simon St.Laurent
http://simonstl.com