XML and WWW

Why the World Wide Web, and not (e.g.) Guide or InterMedia or System-G?

Why the World Wide Web, and not (e.g.) Guide or InterMedia or System-G?

Why the World Wide Web, and not (e.g.) Guide or InterMedia or System-G?

Why the World Wide Web, and not (e.g.) Guide or InterMedia or System-G?

Why the World Wide Web, and not (e.g.) Guide or InterMedia or System-G?

Why the World Wide Web, and not (e.g.) Guide or InterMedia or System-G?

Why the World Wide Web, and not (e.g.) Guide or InterMedia or System-G?

Why the World Wide Web, and not (e.g.) Guide or InterMedia or System-G?

Why the World Wide Web, and not (e.g.) Guide or InterMedia or System-G?

• first off the block
• improved reliability
• innovation
• simplicity

The Web succeeded because it was simple.

Why was it made simple? In order to scale.

Our mission: to lead the Web to its full potential.

Our goals:

• universal access
• semantic Web
• trust
• interoperability
• evolvability (through simplicity, modularity, compatibility, extensibility)
• decentralization
• cooler multimedia

Because of our goals, we care about

A world-wide organization.

• host organizations
  • ERCIM (European Research Consortium for Informatics and Mathematics), Sophia-Antipolis
  • Keio University, Tokyo
  • Massachusetts Institute of Technology, Cambridge, Mass.
• offices in many regions: Australia, Benelux, Finland, Germany/Austria, Greece, Hong Kong, Hungary, Israel, Italy, Korea, Morocco, Spain, Sweden, United Kingdom and Ireland.
  • outreach, publicity, workshops, etc.
  • translations (e.g. the books XML & Co and XHTML, CSS & Co, http://www.edition-w3c.de/#Buecher)
• members from Europe, North America, and Asia

As customers, demand that your vendors support open standards!

As users, read and comment on our draft specifications!

As institutions, join the W3C to give users a stronger voice within the organization!

First, the heritage of SGML (Standard Generalized Markup Language, ISO 8879):

• generic / generalized / descriptive markup (vs. application-specific)
  • for data reuse
  • for data longevity
• (therefore) declarative markup (vs. imperative)
• information has validatable structure

Also:

• simplicity

Some dates: Has XML lost its simplicity?

The syntax of XML is simple:

<doc>
  <rule number="1">Everything is delimited.
    <elucidation>
      <subrule>Elements are delimited by <term>start-</term> 
        and <term>end-tags</term>.</subrule>
      <subrule>Tags are delimited by angle brackets.</subrule>
      <subrule>Attribute values are delimited by 
        quotation marks.</subrule>
    </elucidation>
  </rule>
  <rule number="2">Everything nests.
    <elucidation>
      <subrule>Elements occur within elements.</subrule>
      <subrule>Attributes are specified within start-tags.</subrule>
    </elucidation>
  </rule>
</doc>

Three layers of rules governing data.

Distinguish logical and physical structure.

To every thing there is a season. And a spec.

The original plan:

• XML (a lightweight SGML) 1998
  • generic markup
  • validation
• XLink / XPointer (lightweight HyTime) 2002
  • stand-off links
  • n-way linking
  • structure-based addressing
• XSL (lightweight DSSSL) 1999, 2001
  • structure-based formatting and rendering
  • tree transformations
  • flow objects
• XML applications / XML-based languages (SMIL, XHTML, MathML, ...)

An early addition: XML Namespaces 1.0.

A conceptual stack for markup (or data representation generally).

A conceptual stack for markup (or data representation generally).

A conceptual stack for markup (or data representation generally).

A conceptual stack for markup (or data representation generally).

A conceptual stack for markup (or data representation generally).

A conceptual stack for markup (or data representation generally).

A conceptual stack for markup (or data representation generally).

A conceptual stack for markup (or data representation generally).

A conceptual stack for markup (or data representation generally).

A conceptual stack for markup (or data representation generally).

A conceptual stack for markup (or data representation generally).

XML Information Set: what is information, what is insignificant variation

XML 1.1: alignment with Unicode 3

XML Namespaces 1.1: improve processing on abstract model, re-serialization

A typical data flow diagram.

When you have a good hammer ...

If XML is a good way to represent complex data, then we'll also need:

• APIs for XML
  • Document Object Model (DOM)
  • Simple API for XML (SAX)
• XML querying
  • XPath
  • XQuery
  • XSLT
• XML-to-XML transformations
  • XQuery
  • XSLT
• XML messages for distributed applications
  • SOAP
  • Web Services description, choreography
  • Digital signatures, encryption

as well as definitions for specific XML applications (e.g. for corpora, for historical philological editions, for commerce of various kinds, ...)

• ownership of information
  • freedom from vendor lock-in
  • freedom from pre-defined semantics
  • application independence

• ownership of information
  • freedom from vendor lock-in
  • freedom from pre-defined semantics
  • application independence
• responsibility for information
  • You must think about the processing you need.
  • You must decide what information you wish to capture, and what information you wish to discard.
  Sometimes painful, but worthwhile.

For more information: http://www.w3.org/XML