Overview of W3C Technologies

Ivan Herman, W3C Head of Offices

SURFNet Relatiedagen 2002

Egmond aan Zee, 12 November, 2002

http://www.w3.org/2002/Talks/SURFNet-Egmond-IH/

• W3C was formed in 1994 by Tim Berners-Lee
  • first "host" at MIT, Cambridge, USA
  • two more "hosts" joined later
    • INRIA, France
    • Keio University, Japan
  • there are 13 "offices" as local representations
• W3C is a member organization (around 450 members)
• Liaisons with more than 27 external organizations

• W3C develops recommendations ("Web Standards")
  • developed by Working Groups
  • Working Groups are staffed by members
  • all members can be represented in working groups
  • neutrality and consensus are our keywords
  • the process also includes:
    • public comments
    • calls for implementations
• Other activities at W3C
  • proof-of-concept software development (open source)
  • education, outreach, guidelines
  • tutorials
  • validator services (eg, for XHTML, CSS, RDF, Schemas, ...)

Web Technologies should be interoperable

• The Web is based on a large palette of technologies
• No technology can pretend to cover all needs on the Web
• Hence the interoperability of technologies is a must!

The Web is for everybody, regardless of:

• Language
• User capabilities
• Device used for access
• ...

• XML is a key technology to ensure interoperability
• But XML, by itself, is not really useful... we need to
  • have datatypes, validation (DTD-s, Schemas, ...)
  • mix XML applications (Namespaces)
  • link (XLink, XBase,...)
  • compose/decompose (XInclude, Fragments, ...)
  • refer to XML data content (XPath, Query, ...)
  • transform (XSLT)
  • encrypt, decrypt, sign (Signature, Encryption, ...)
  • interact, script (DOM, Events, ...)
  • etc
• W3C is active in all these areas

• Cover various means of human interaction:
  • documents (XHTML, MathML)
  • graphics, multimedia (SVG, SMIL)
  • voice (VoiceXML)
• Separation of presentation and content is a major principle
  • CSS and XSL are the key technologies for this

• Most of them are XML applications
  • W3C has some non-XML technologies, too (WebCGM, PNG)
• They are all fairly mature by now
• For all of them tools and implementation emerge
• Greatest challenge for coming years: integration
  • usage of XML is the key
  • example: integration of MathML, XHTML, and SVG in Amaya

• Computers co-operate through the Web
  • goal is to achieve a better user experience
• Typical applications:
  • search engines, on-line catalogues, news services, ...
  • user profiling, e-commerce, shared computing resources, ...
  • computational services (stock values, translations, weather data, ...)
• Two major approaches emerge:
  1. (remote) procedure based
  2. data based

• Providers expose services as procedures ("remote functions")
• "Users" can call these functions through the Web

  (transferring data as input and/or output)

• Data can be transferred to and from remote functions
• Call sequence patterns can be defined for complex applications

• All major steps can be described in XML:
  • protocols to transfer data over the Net (SOAP)
  • description of the procedure interfaces (WSDL)
  • etc
• Area collectively known as Web Services
  • an old concept revived by the Web
  • one of the most active areas of development today

• Metadata is added to Web resources
  • they describe properties of the resource
  • W3C's RDF gives a unified format to do this
• Metadata vocabularies (ontologies) can be developed
  • allows for logical reasoning on the metadata, eg
    • "if this property is true, then that property is true..."
    • "this property is that same as that property..."
    • etc
  • W3C develops a Web Ontology Language
• Applications are based on analysing the metadata
  • eg, search engines

• Metadata refer to general URI-s
  • one can define metadata on data somewhere else
  • "cataloging services" become feasible, for example
  • the Web can be viewed as a big database with sophisticated

    search and retrieval facilities

• This is the area of the Semantic Web
  • "an infrastructure for reasoning on the Web"

• W3C stores metadata about its own homepage news
  • using a vocabulary called RSS
• Other news services extract these news items...
• ...and incorporate them in their own news services
• For example: Meerkat of O'Reilly, or NewsIsFree.com
• The metadata is stored publicly; no extra procedure is

  necessary to get the news

• It is also be possible for third parties to publish metadata

  about the W3C home page news!

The two technologies complement one another!

and

For example: Semantic Web based search engines for Web Services

("find me the best remote procedure that does this and that...")

• Regardless of language
  • the majority of Web users are not English speakers
  • it is not only an issue of character sets...
    • directions of writing, ...
    • format of dates, phone numbers, ZIP codes, "bulleted item" types, ...
    • different keyboard types, ...
• Regardless of user capabilities
  • color or total blindness, ...
  • difficulties with a keyboard, mouse (eg, RSI problems), ...
  • dyslexia, cognitive or neurological difficulties, ...
• Regardless of device types and capabilities
  • PC-s, (portable) phones, TV-s, PDA-s, ...
  • low bandwidth, small B/W screen, no sound, no screen, ...

• XML formats should encompass all needs
  • eg, proper data structures for dates, facilities for metadata
• The infrastructure should adapt itself. This means:
  • separation of the information from the presentation
  • tools to describe environments and let the tools adapt
    • the Semantic Web has an important role to play!
• Related activities at W3C:
  • "horizontal" review of all W3C technologies for internationalization,

    multimodality, accessibility, device independence...

  • education and outreach, information for designers, quicktips

• Results: close to 50 recommendations (!)
• These technologies are not developed by the W3C team...
  • there are only around 65 people, including the admin...
• ...instead, they are done with all the members
• Join W3C to influence the development!
• We are all in it together...

W3C home page:

http://www.w3.org

These slides:

http://www.w3.org/2002/Talks/SURFNet-Egmond-IH/

More information about W3C:

http://www.w3.org/Consortium/

Contact information for the Benelux Office:

http://www.w3c.nl

General contact information:

http://www.w3.org/Contact/

Mail me:

ivan@w3.org