The World Wide Web Consortium
C. M. Sperberg-McQueen,
Co-chair, W3C XML Schema Working Group
Co-chair, W3C XML Coordination Group
Domain Lead, W3C Architecture Domain
XML World 2001
San Francisco, California
27 November 2001
W3C is the birthplace of XML, but there's more to XML than one
specification. The XML family of technologies is largely developed
within the W3C XML Activity. Michael will provide an overview of the
current and planned work of the W3C XML Activity, and address
questions related to specific topics including XML Schema, XML Query,
- XML: the little idea that grew
- What's new in XML at W3C?
- who/what is the W3C?
- organization of XML activities in W3C
- status of the working groups
- other relevant W3C activity
2. XML: the simple idea
At heart, XML is a simple idea:
- Text is not just a sequence of characters.
- Text is not just an arbitrary mixture of
characters with commands.
- Text has structure.
Information has structure.
Information formats should expose that structure.
3. XML: the simple idea
If information formats expose the structure of information,
- Information can be richer, more variable, more subtle.
- Software can be stupider simpler, cheaper,
If we can't have intelligent software, let's at least
have well-informed software.
4. XML: the simple idea
Nothing in XML is new.
It all (start-tags, end-tags, elements, attributes, tree structure,
entities, document grammars) came straight out of
The original goals of the XML activity were:
- make SGML usable on the Web
- add structure to Web documents
- be simple (25 pp.), clean (validity)
5. Growth of XML
XML has grown beyond its original goals:
- make SGML and HyTime, and DSSSL usable on the
- add structure to Web documents and data
6. Growth of XML
allow arbitrary data to be exposed on Web in XML
- make XML usable in specific applications:
- improve metalanguage for defining languages
- authenticate with digital signature
- canonicalize so signatures are more robust
- use XML for program-to-program communication
- use XML as the basis for Web Services
7. What's new at W3C?
- Who is W3C?
- How is XML work organized at W3C?
- What's cooking?
8. Who is the W3C?
The World Wide Web Consortium is a member-supported organization
which creates Web standards.
to lead the Web to its full potential.
9. W3C goals and operating principles
- universal access
- semantic Web
- evolvability (through simplicity, modularity, compatibility,
- cooler multimedia
10. Organization of work in W3C
Domains and Activities:
- Architecture Domain
- Technology and Society Domain
- Document Formats Domain
- Interaction Domain
- Web Accessibility Initiative
11. Architecture Domain
- XML Activity
- XML Core WG
- XML Linking WG
- XML Schema WG
- XML Query WG
- DOM Activity
- XML Protocols Activity
- Jigsaw (open-source Web server)
12. Technology and Society Domain
- Electronic commerce
- Privacy (P3P)
- XML encryption
- XML signatures
- Metadata (RDF, Semantic Web)
13. Document Formats Domain
14. User Interface Domain
- Device independence (mobile access, TV and the Web, CC/PP)
- Synchronized multimedia (SMIL)
- Voice Browser (VoiceXML, speech recognition and synthesis, ...)
15. Web Accessibility Initiative
- WAI International Program Office
- WAI Technical Activity
- XML Accessibility Guidelines
18. XML Core WG
Chairs: Paul Grosso, Arnaud Le Hors
- XML 1.0 Second Edition, ed. Eve Maler (XML 1.02e)
- XML updates for Unicode 3.x (XML Blueberry)
(Requirements out, draft out)
- XML Information Set (Rec)
- XML Inclusions (XInclude) (Last Call completed)
- Errata for existing specs
- XML Namespaces 1.1
- Classification of XML Processors
19. XML Linking
Chair: Henry Thompson
- XLink (standoff links, multi-ended links, better role labeling)
- XML Base (relative URI support)
One Candidate Recommendation:
- XPointer (addressing into XML)
20. XML Schema
Chairs: Dave Hollander, Michael Sperberg-McQueen
XML Schema, parts 0, 1, and 2 a W3C Recommendation.
- entities/special characters work
- formal description of XML Schema
- work on test suite
21. XML Schema Highlights
Like DTDs, but:
- in XML document syntax
- coherent account of schema validation across multiple
- modular construction of vocabularies
- full validation, partial validation (black boxes, white boxes)
- simple datatypes
22. XML Query
Chair: Paul Cotton
Toward an XML Query language for all XML data:
- XQuery 1.0 and XPath 2.0 Data Model
- XQuery 1.0 and XPath 2.0 Functions and Operators
- XML Query Use Cases
- XQuery 1.0 Formal Semantics
- XQuery 1.0: An XML Query Language
- XML Syntax for XQuery 1.0 (XQueryX)
23. XML Query Highlights
- element selection (XPath++)
- strong static typing
- dynamic type checking
- keyword syntax and XML syntax
- generate arbitrary XML results
Chair: Philippe Le Hégaret
Document Object Model (DOM) Level 2
- Traversal and Range
25. DOM, continued
- Level 2 HTML DOM
- Level 3 Core
- Level 3 Views and Formatting
- Level 3 Abstract Schemas and Load and Save
- Level 3 Events
26. DOM Highlights
- an intelligent API for document manipulation
- browser-independence* of scripting code
- crucial tool for power users and system integrators (this
- support for editors ...
27. XML Protocols
Chair: David Fallside
Goal: create a simple foundation for program to program
communication using XML.
- Requirements document
- XML Protocol Abstract Model
- SOAP 1.2 Working Drafts
- Part 1: Messaging Framework
- Part 2: Adjuncts
Chair: Sharon Adler
XSLT a W3C Recommendation since November 1999
XSL (aka XSL FO) now also a Recommendation
Work underway for XPath 2, XSLT 2 (extensibility, XML Schema type support)
29. Semantic Web
- enabling standards (RDF/XML)
- and support technologies (software)
to facilitate the creation of machine readable
metadata on the Web for more effective
- automation, and
of networked information.
- Semantic Web Activity headed by Eric Miller
- Advanced Development headed by Ralph Swick
30. RDF Core WG
Chairs: Brian McBride, Dan Brickley
Resource Description Framework: a low-level model for
Basic model: labeled directed graph.
- RDF Model and Syntax (Recommendation)
- RDF Schema (Candidate Rec)
31. RDF -- the basics
To describe a resource, you need
a vocabulary in which to describe it.
The problem is that in a world-wide Web with universal access,
we cannot rationally assume that we know in advance everything
anyone might wish to say.
No closed-world assumptions!
So -- define a vocabulary ... but also specify
a more fundamental extensible semantic system in which it
32. RDF -- the minimum
To say something about something
describe some property/ies of your subject
You need at least:
- a way to name the subject (URI)
- a way to identify the property you are giving (label,
- a way to give the value of a property (literal, or URI)
33. Intellectual property
Does anyone like software patents?
Can anyone do anything about them?
And what do we do in the meantime?
34. W3C Patent Policy
The key components of the draft W3C patent policy:
- disclosure (no* submarine patents)
- commitment in advance to terms
- essential technology
- possible opt-out
- viral effect
- royalty-free vs. `reasonable and
35. Some myths and facts
- "W3C is loosening its policy."
- No, W3C is tightening its policy.
36. Myth/Fact No. 2
- "W3C used to grant royalty-free licences, and now
you're planning to extract royalties."
No, W3C has never had licensing terms
attached to implementation of W3C Recs.
W3C documents and open-source
software continue to be available on the same terms as before.
37. Myth/Fact No. 3
Without disclosure, the true state of technology
is not RF, not RAND, but FUD.
- "Everyone knows the Internet is fundamentally
royalty-free. Why change now?"
- Many people do believe so, but not everyone agrees.