News Release: W3C Releases First Working Drafts for XML Schema Specification

Press Release URI:
http://www.w3.org/1999/05/schema-1st-wd.html

XML Schema Working Draft:

http://www.w3.org/TR/xmlschema-1/
http://www.w3.org/TR/xmlschema-2/



World Wide Web Consortium Releases First Working Drafts of XML Schema
Specification

W3C Members Collaborate to Improve and Standardize Needed Technology

Contact
America, Asia --
      Janet Daly, <janet@w3.org>, +1.617.253.5884
Europe --
      Josef Dietl, <jdietl@w3.org>, +33 4.92.38.79.72


http://www.w3.org/ -- 6 May, 1999 -- Leading the Web to its full
potential, the World Wide
Web Consortium (W3C) today releases the first public working drafts of
the XML Schema
specification: XML Schema Part 1: Structures and XML Schema Part 2:
Datatypes. By
publishing these working drafts at an early stage of the design work,
W3C is ensuring that
the public can follow the XML Schema design work, and that the final
result can be widely
accepted and adopted.

One part proposes facilities for associating datatypes with XML element
types and
attributes; this will allow XML software to do a better job of managing
dates, numbers, and
other special forms of information. The other part of the specification
proposes methods for
describing the structure and constraining the contents of XML documents.
These drafts,
which builds on earlier work submitted to W3C by several vendor and user
organizations,
are the first step in the development of a powerful, vendor-neutral
format for defining the
rules that govern particular kinds of XML data.

Industry-Wide Participation

Current members of the W3C XML Schema Working Group are key industry
players in
Web publishing, XML processing, and database management system. In
alphabetical order,
they are: Adobe Systems, Agranat Systems, Arbortext, University of
Bristol, Calico
Commerce, Commerce One, University of Edinburgh, Extensibility, Graphic
Communications Association, Health Level Seven, HP, IBM, University of
Illinois at
Chicago, Inso, Lawrence Berkeley National Laboratory, Lotus Development,
Louisiana
State University, Merrill Lynch, Microsoft, Microstar, Object Design,
Omnimark
Technologies, Oracle, SAP, SoftQuad, Software AG, Sybase, Vignette, Wall
Data, and
Xerox.

Following W3C's practice, the XML Schema Working Group provides a public
mailing list
for comments on the working drafts, in addition to the feedback channels
defined by the
W3C Process. The address for comments is given in the drafts themselves.

The Web needs Richer Data

Extensible Markup Language (XML) was originally designed for encoding
human-readable
documents, but quickly attracted attention from groups interested in
electronic commerce,
interchange of data from relational and object-oriented databases, and
other non-document
applications. The Resource Description Framework (RDF) was designed to
integrate a
variety of web-based metadata activities including content ratings,
search engine data
collection, and digital library collections. Many applications can
benefit from the
development of schemas:

      Databases must, for example, communicate detailed information
about the legal
      values of particular fields in the data being exchanged.

      Publishing and syndication services must be able to describe the
properties of
      headlines, news stories, thumbnail images, cross-references, etc.

      For electronic commerce, schemas can be used to define business
transactions within
      markets and between parties, and to provide rules for validating
business documents.

When XML is used to exchange technical information in a multi-vendor
environment,
schemas will allow software to distinguish data governed by
industry-standard and
vendor-specific schemas, and help applications know when it is safe to
ignore information
they do not understand, and when they must not do so. This means schemas
may help
make software more robust and systems more able to change and adapt to
evolving
situations.

Traditional document processing will also benefit from XML Schemas,
because
schema-aware document management systems will be better able to guide
authors and
editors in the creation and maintenance of documents.

XML, in accordance with its origin, provides methods of expressing
syntactic validity
constraints on document content, without attempting any formal
specification of the
meaning of markup. RDF, starting from the problem of describing Web
resources in
general, has focused more on the semantics of metadata, and less on the
syntax. One of the
most important design challenges for the ongoing work on XML Schemas and
RDF is to
ensure that their approaches and data models converge.

What's new?

At present, rules about what kinds of information can appear in an XML
document can be
expressed only in the form of XML document type definitions (DTDs). DTDs
use a special
format to define the rules for using XML markup for different kinds of
documents, but in
practice there are some common rules that cannot be expressed at all in
DTD form. XML
Schemas are more powerful than DTDs, so they will be able to express
some rules that
DTDs cannot express.

Even more important for many purposes is that XML schemas are themselves
XML
documents. Using XML as the document format for schemas, instead of
using a
special-purpose form as DTDs do, will allow users and developers of XML
schemas to use
standard XML tools, the same ones they use for other structured
information, instead of
having to shift to specialized tools for work on schemas. It will also
remove some of the
shroud of mystery that have traditionally made DTD development a black
art. Any existing
XML processor can read an XML schema; interchange will be easy.

Cooperation Promotes Widespread Adoption

The XML Schema Working Group began its work by attempting to clarify the
scope of its
work. Requirements and suggestions have been gathered and discussed;
eventually, these
were refined into a short requirements document, which outlines some of
the core usage
scenarios and assumptions that are governing the design of the XML
Schema language.

The XML Schema work builds on existing W3C specifications and experience
in XML and
database fields. The intense work of preparing these drafts has
harnessed the expertise of
key players among the W3C Membership in the fields of document
management, database
management, and electronic commerce. The diversity of representation
within the W3C
working group helps ensure that XML Schemas will be an open,
vendor-neutral format that
content creators can easily use and depend upon for information
interchange over the Web.
The purpose of these publications is to encourage public comments and
contributions.

Further information on XML Schema work can be found in the XML Activity
statement at
http://www.w3.org/XML/Activity


About the World Wide Web Consortium [W3C]

The W3C was created to lead the Web to its full potential by developing
common protocols
that promote its evolution and ensure its interoperability. It is an
international industry
consortium jointly run by the MIT Laboratory for Computer Science (MIT
LCS) in the
USA, the National Institute for Research in Computer Science and Control
(INRIA) in
France and Keio University in Japan. Services provided by the Consortium
include: a
repository of information about the World Wide Web for developers and
users, sample code
implementations to embody and promote standards, and various prototype
and sample
applications to demonstrate use of new technology. To date, over 300
organizations are
Members of the Consortium.

For more information about the World Wide Web Consortium, see
http://www.w3.org/


___________________________________________
Janet Daly
Head of Public Relations, W3C

MIT/LCS                               +1 617 253 5884 (voice)
NE43-344                        +1 617 258 5999 (facsimile)
545 Technology Square                          janet@w3.org
Cambridge, MA 02139                  http://www.w3.org/

Received on Thursday, 6 May 1999 15:05:04 UTC