Re: XML Schema usage statistics (WAS: Draft minutes of 2009-05-12 TAG weekly)

Noah, 

The sentiments you express in this case --- "There's no way I'm
going to spend years working in the W3C if ..."
are shared by those who invested many years of their lives
working on XHTML "because --- in 1998, at the `future of html
workshop', W3C declared that as the *future direction*".

Glad to see that in this case you appreciate a point of view that
is shared with you by a large portion of the XHTML/clean-markup
community.
Incidentally, the questions Rick asks about XSD if answered would
be a far less revolutionary change than abandoning
clean,well-formed markup  in favor of TAAG-soup. 


noah_mendelsohn@us.ibm.com writes:
 > (I'm writing here as a TAG member, not as chair)
 > 
 > Ashok Malhotra wrote:
 > 
 > > I have some trepidation about this line of reasoning which would 
 > > seem to be: XML Schema is widely used, therefore it is good and 
 > > should continue!
 > 
 > I have some trepidation about what's going on here, but for somewhat 
 > different reasons.  After XSD 1.0 went to Recommendation, the XML Schema 
 > Working group was rechartered (more than once, FWIW).  Here are some 
 > quotes from the latest charter [1], under which the Candidate 
 > Recommendation [2,3] has been published:
 > 
 > "The XML Schema working group will maintain and revise the XML Schema 
 > specification developed beginning in 1998 and published as a W3C 
 > Recommendation on 2 May 2001. "
 > 
 > [...]
 > 
 > "Goals: to finish publication of version 1.1 of the XML Schema 
 > Recommendation, which corrects known errors and makes modest improvements 
 > to the language, and do preparatory work for a possible version 1.2. 
 > Changes in function or syntax incompatible with XML Schema 1.0 have been / 
 > will be made only if the resulting improvements compellingly justify the 
 > loss of interoperability with existing systems and documentation. Some 
 > substantive changes have been made in the interests of aligning version 
 > 1.1 with the needs of the XML Query 1.0, XPath 2.0, and XSLT 2.0 family of 
 > specifications and with XML 1.1. Requests for substantive changes may also 
 > come from other groups. [plus other goals not quoted]"
 > 
 > Now, spurred by Rick Jelliffe's request [4], we're asking a question that 
 > boils down to:  "shouldn't the W3C cancel this effort to provide 
 > incremental improvements to Schema 1.0, and instead start on a new, 
 > cleaner language?"
 > 
 > I strongly believe that this is a question that should have been settled, 
 > and indeed was settled, when the working group was chartered with the 
 > above goals.  The charter very clearly says:  build on the XSD 1.0 base, 
 > and to the extent possible, retain syntactic compatibility. (There is a 
 > later goal that allows for experimentation with new syntax too, but that's 
 > in addition to not instead of enhancing the existing syntax; nowhere is a 
 > brand new language core discussed.)  The W3C membership has every 
 > opportunity to provide guidance on the content of such charters, and the 
 > time to consider proposals for a new language would have been when the 
 > charters were written.
 > 
 > To change the goals of an effort like this now is not only counter to the 
 > letter of the W3C process, it's hugely disruptive both in this particular 
 > case and as a precedent.  There's no way that people like me are going to 
 > devote years to working in the W3C, toward agreed goals, if at the end we 
 > say: never mind, those weren't the goals. 
 > 
 > Rick raises some interesting and important technical points about XSD.  No 
 > doubt it has shortcomings, though I don't necessarily agree with all that 
 > he lists.  I also think XSD has some strengths, which he tends to 
 > de-emphasias, and FWIW the other languages have their own shortcomings, 
 > but my point here is not to claim that XSD is better, or that if I were 
 > starting from scratch I might not look very hard at just the technical 
 > direction that Rick proposes.  The fact is that most of these concerns 
 > have been understood in general for a long time and Rick among others has 
 > raised them for a long time.  Most of them were understood when the 
 > decision was made to create a charter that would focus on improving the 
 > experience of the many users who have adopted the W3C XML Schema 
 > Recommendation.  We, the W3C, decided to invest in maintaining and 
 > enhancing a Recommendation that was being widely adopted.
 > 
 > Indeed, evidence is clear that there is very widespread use of XSD, 
 > arguably extraordinarily widespread use of XSD, and so lack of adoption is 
 > in no way a reason to revisit the charter goals now.  That is, IMO, the 
 > only reason we are in this thread considering relative rates of adoption 
 > of these languages at all.  The fact is that XSD 1.0 is very widely used, 
 > and XSD 1.1 is designed to make the language more valuable for the many 
 > users who have invested in it.  XSD 1.0 is also a W3C Recommendation, and 
 > while I have no problem with the W3C considering alternative languages on 
 > the merits from time to time, the presumption should be that we support 
 > and maintain our Recommendations, and that we honor our agreed charters.
 > 
 > Noah
 > 
 > P.S. The question of which schema languages are how widely used remains an 
 > interesting one, and if I turn up any useful facts based on my inquiries 
 > in IBM [5] I will pass them on.  So far, all the evidence I've seen 
 > suggests that XSD is more widely used than the other languages by many 
 > measures, and by quite a significant margin, though there are interesting 
 > communities that strongly prefer RelaxNG and/or Schematron.  There appear 
 > to be more .xsd documents accessible on the Web; I believe XSD is used by 
 > more widely-deployed tooling; and preliminary investigations suggest that 
 > XSD is used normatively by more "vertical" XML standards (some using XSD 
 > alone, and some using XSD+Schematron) than the alternatives. Of course, 
 > XSD also forms the type system for W3C XML Query, XSLT 2.0, and XPath 2.0. 
 >  As I say, I'm still trying to check the facts on those adoption claims, 
 > and I'll pass on what I can. 
 > 
 > [1] http://www.w3.org/2006/06/XML/schema-wg.html
 > [2] http://www.w3.org/TR/2009/CR-xmlschema11-1-20090430/
 > [3] http://www.w3.org/TR/2009/CR-xmlschema11-2-20090430/
 > [4] http://lists.w3.org/Archives/Public/www-tag/2009May/0021.html
 > [5] http://lists.w3.org/Archives/Public/www-tag/2009May/0046.html
 > 
 > --------------------------------------
 > Noah Mendelsohn 
 > IBM Corporation
 > One Rogers Street
 > Cambridge, MA 02142
 > 1-617-693-4036
 > --------------------------------------
 > 
 > 
 > 
 > 
 > 
 > 
 > 
 > 
 > ashok malhotra <ashok.malhotra@oracle.com>
 > Sent by: www-tag-request@w3.org
 > 05/18/2009 07:05 PM
 > Please respond to ashok.malhotra
 >  
 >         To:     "T.V Raman" <raman@google.com>
 >         cc:     www-tag@w3.org, (bcc: Noah Mendelsohn/Cambridge/IBM)
 >         Subject:        Re: XML Schema usage statistics (WAS:  Draft 
 > minutes of 2009-05-12    TAG  weekly)
 > 
 > 
 > I have some trepidation about this line of reasoning which would seem to 
 > be:
 > XML Schema is widely used, therefore it is good and should continue!
 > 
 > I think we need to ask some more nuanced questions.  For example
 > 1. Clearly all the statistics are based on Schema 1.0.  Are the 
 > additions in 1.1 beneficial, necessary or excess baggage?
 > Should the Schema WG be rechartered to add yet more features.
 > 2. Is there a core subset of features in XML Schema that is heavily used 
 > and can be isolated?  If so, should we consider a profile?
 > 
 > I'm sure you smart folks can think of other good questions!
 > All the best, Ashok
 > 
 > 
 > T.V Raman wrote:
 > > It would also be enlightening to find out how many of those XSD
 > > files were generated from rng/ files. I know for a fact that many
 > > groups inside W3C  routinely produce their obligatory xsd schema
 > > for their specs by first creating rng files.
 > >
 > > Julian Reschke writes:
 > >  > Paul Cotton wrote:
 > >  > > From the draft May 12 TAG minutes:
 > >  > > 
 > >  > >> raman: XML Schema hasn't worked out very well. I'm skeptical that 
 > it 
 > >  > > really dominates
 > >  > > ...
 > >  > >> timbl: Skeptical about preponderance of XSD usage, would like to 
 > see some 
 > >  > > figures
 > >  > >> noah: Any volunteers?
 > >  > >> (silence)
 > >  > > 
 > >  > > Searching Google code for .xsd files (
 > http://www.google.ca/codesearch?hl=en&lr=&q=file%3A.*%5C.xsd%24) finds 
 > 44,800 files.
 > >  > > 
 > >  > > Searching Google code for .rng files (
 > http://www.google.ca/codesearch?hl=en&lr=&q=file%3A.*%5C.rng%24) finds 
 > only 3,000 files.
 > >  > > 
 > >  > > Not necessarily a reliable survey but it certainly indicates that 
 > in publicly visible code stores indexed by "Google code" .xsd file 
 > occurrence is significantly greater than that of Relax NG files. 
 > >  > > 
 > >  > > Personal opinion: I expect that the ratio in enterprise systems 
 > whose code stores are not visible to a tool like "Google code" that this 
 > ratio would be even more slanted towards XML Schema.
 > >  > > 
 > >  > > /paulc
 > >  > > ...
 > >  > 
 > >  > Plus ~1000 in RNC (Compact) format.
 > >  > 
 > >  > It would be interesting to have a comparison of the # of 
 > specifications 
 > >  > that use XSD, RNC, or RNG as part of the spec text.
 > >  > 
 > >  > BR, Julian
 > >
 > > 
 > 
 > 

-- 
Best Regards,
--raman

Title:  Research Scientist      
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Received on Tuesday, 19 May 2009 17:52:16 UTC