Presentation organized by the Delhi Chapter of the IEEE, and held at the Indian Institute of Technology, on the 8^th of February, 2006. The presentation was held on behalf of the W3C Indian Office.

World Wide Web Consortium (W3C)

“To lead the World Wide Web to its full potential by developing protocols and guidelines that ensure long-term growth for the Web”

• Founded by Tim Berners-Lee in 1994
• Develops open Recommendations (Web Standards)
  • over eighty so far…
• Engages in education, outreach, develops guidelines…
• A neutral forum for building consensus around Web standards

A high level overview

• This presentation does not go into all the technical details everywhere
• The goal is to give a feeling how technologies fit together

Some guiding principles at W3C

• 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 necessary
• Web Standards should be open, i.e., non-proprietary
• The Web should be accessible to all

W3C’s long term goals

• Web for Everyone
  • regardless of language, user capabilities, geographical location, device used for access,…
• Web on Everything
  • not only PC-s, but Phones, PDA-s, Television,…
• Knowledge Base, Advanced data searching and sharing
  • information for both human and machine processing
• Trust and Confidence
  • technologies for collaborative environment
  • a Web with accountability, security, confidence, and confidentiality

The W3C technology stack…

First, the foundations…

The foundations

• Two major data models, used for different purposes:
  1. XML Infosets, the basis for XML and its applications:
     • models strongly hierarchical (tree) structures
     • abstracts out from the syntax what XML is (it is a bit like numbers and numerals…)
     • all newer XML based recommendations rely on Infosets, separating the abstract concept from the syntax
  2. RDF(S) Graphs, the basis for Semantic Web:
     • models loose connections among Web resources
     • connections among URI-s are labelled (referred to as “properties” or ”predicates”)
• Both are keys for interoperability
• Most of W3C’s recommendations are based on these foundations

But, by themselves, these are not enough…

• For XML, we need further specifications to form a coherent environment
  • have data types, validation (DTD-s, Schemas, …)
  • mix XML specifications/applications (Namespaces, XInclude, …)
  • use hyperlinks (XLink, XBase, …)
  • refer to, and navigate in XML data, access to XML Databases (XPath, Query, …)
  • transform (XSLT)
  • interact, script (DOM, Events, …)
  • efficient interchange of data
  • etc.
• For RDF(S), some basic facilities are also necessary
  • access to RDF depositories, databases (SPARQL)
  • provide a textual interchange format for RDF Graphs (RDF/XML)

The current status of some of these

• Some of the technologies are stable and widely used (e.g., DTD-s, Schemas, Namespaces, XSLT, XPath, DOM, RDF/XML, …)
  • new releases might even appear soon (e.g., XSLT2, XPath2, …)
• Others are under development, though quite mature and with already lots of users (e.g., XQuery, SPARQL)
• Others have just begun to be developed (e.g., Efficient XML Interchange, a.k.a. “Binary XML”)
• Some further work on the fundamentals is also necessary (e.g., new versions of Infoset, XML Processing)

Web applications…

A rich set of possibilities exist already…

• Technologies for:
  • text documents (XHTML, MathML)
  • graphics, multimedia (SVG, SMIL)
  • interactive forms (XForms)
  • controlling presentation (CSS)
  • …
• These are all well known and more or less widely used
  • these very slides use XHTML, CSS, DOM Scripting, and SVG…

New challenges

• Most of these technologies are well known, some (e.g., XForms) have come to the fore lately
• There are still challenges:
  • integration various XML formats seamlessly
    • example: integration of MathML, XHTML, and SVG in Amaya within one XML document
    • problems are: how to manage events, focus, navigations; how to manage combined DOM trees from scripts, …
    • Web Integration Compound Document (WICD) Core 1.0 describes the correct combination of XHTML+CSS+SVG
    • Compound Document by Refernce Framework (CDF) describes generic rules and behavior for combining XML based languages
  • “Web Applications”
    • interoperability of tools to develop client-side applications like GMail, games, auction sites, e-commerce, …
    • W3C has just started a new activity in this area, developing:
      • Standard Web API-s (e.g., drag-and-drop, HTTP access)
      • Web Application Formats, like XBL, providing bridges between the declarative and scripting aspects

The mobile web…

What is “Mobile”?

• Currently W3C concentrates on mobile/cell phones and network aware PDA-s
  • but a workshop on Ubiquitous Web has just been announced!
• Extremely dynamic market: ≈800M units sold in 2005, 63% of installed phones are Web capable (est.)
• Potentially huge number of users in developing countries (where, for many people, mobile is the only gateway to the Web/Internet!)

The web usage is still evolving

• 50% of web-capable phones not set up to use the Web
• 24% of web-capable phones used only once for Web access
• Total: 74% of web-capable phones not really used
• But there are also positive signs:
  • Browsing is number one data packet usage these days (Nokia Study, 2005)

Restrictions, constraints

• Restrictions:
  • small memory, slower processors, small bandwidth, …
• Constraints:
  • small overall size, screen and keyboard (or no keyboard at all)
  • different usage environments (on the street, on a train…)
  • hands-free, one handed, or two handed usage
  • most users are non-technical
• Technical restrictions may become less relevant, but the constraints are bound to stay!
• But: constraints drive innovation!

A World of varieties

The Players

• Lots of hardware and software vendors (of course)
• Two main industry consortia:
  • Open Mobile Alliance (OMA):
    • integrates a number of older consortia (WAP Forum, SyncML Initiative,…)
    • specifies interoperable technical specification for Mobile devices
  • 3rd Generation Partnership Project (3GPP)
    • specifies technical specification for 3rd Generation GSM networks
  • roughly: 3GPP is the radio, OMA is the application level
    • but there are overlaps; they try to cooperate and synchronize
• Java is very well established on Mobiles (a technology to be aware of)

Position of W3C

• OMA and 3GPP often integrate existing technologies (when available and possible)
  • e.g., 3GPP’s Multimedia Messaging Service (MMS) specifications defines the media formats in terms of other technologies
  • if the technology does not exist, they define it themselves
• W3C’s expertise lies in the basic Web architecture
• W3C provides already a number of “building blocks”
  • these may be (or are) integrated in 3GPP/OMA specifications
  • some technologies are used directly
  • W3C strong cooperation with both OMA and 3GPP

An example: SMIL

• SMIL is an integrator language:
  • coordinates the display of other media in time (audio, video, graphics, texts)
  • relies on other media formats for real display
• SMIL 2.1 (version published in December 2005) has a number of profiles
  • SMIL 2.1 Mobile Profile, is identical to 3GPP’s Multimedia Messaging (MMS) format
  • SMIL 2.1 Extended Mobile Profile adds some features (eg, animation)

Another example: SVG Mobile

• SVG has two “Mobile profiles”: Tiny and Basic
• Several implementations exist already
  • newer phones come with SVG built in (Motorola, Nokia, Sharp, SonyEricsson, …)
    • 97 different types in February 2006
  • some Web Browsers on mobile devices have SVG Tiny built in (Opera, NetFront, …)
• W3C is working on SVG 1.2 Tiny (in strong synchrony with 3GPP)
• SVG Mobile becomes the vector graphics tool for Mobile!

W3C’s Mobile Web Initiative (MWI)

“Making Web access from a mobile device as simple, easy and convenient as Web access from a desktop device”

• Complements the work of OMA and 3GPP (but has strong ties to those), and also complements the work done elsewhere at W3C
• Launched in May 2005 with a separate set of directed sponsorship (Nokia, France Telecom, Vodafone, Jataayu, HP, …)
• Two directions of work (more may come):
  • Mobile Web Best Practice Working group:
    • develops a Best practices document: practical advice on creating content for mobile devices
  • Device Description Working Group:
    • develop an infrastructure to make independent device descriptions available to all developers

Voice…

Voice Framework

• The W3C Voice Framework consists of:
  • VoiceXML: a simple dialog control
  • Speech Recognition Grammar Language (SRGL)
  • Speech Synthesis Markup Language (SSML)
  • Semantic Interpretation for Speech Grammar (EMMA)
  • Call Control Markup Language (CCXML)
• First three are already mature and are deployed (with new releases coming)
  • see, e.g., SAP’s VoiceXML demo

Speech recognition

• SRGS is a W3C Recommendation (since 2004)
• Is usually used in conjunction with VoiceXML, but can also be used independently
• Describes the expected utterances with a simple grammar
• Speech processors know what they can expect in a context, hence no need for a fully general speech recognition system
  • this makes speech input feasible
  • the “output” is the set of literals described by the grammar
• The grammar can also be used for non-speech input (eg, to interpret handwritten input)
• There is a semantic tagging work ongoing to add information on interpretation of specific utterances

Speech generation

• Possible output described in text format for text-to-speech generation; but direct inclusion of pre-recorded voice is also possible
• Tags and attributes to control text-to-speach: gender, age, emphasis, language, etc.
• Serious internationalization issues are bound to this technology
  • e.g.: are there tags to properly denote variants in tonality for Chinese, Vietnamese, Korean?
  • W3C organizes a series of workshops around this: 2005 in Beijing, 2006 (planned) in Greece concentrating on Middle Eastern languages, maybe another in 2006 or 2007 for Indic languages, etc.

VoiceXML

• Defines the dialog with the user, handles task switching, event handling, errors, timeouts, etc
  • defines a complex finite state machine
• Can use Speech recognition and speech generation as I/O, but not exclusively:
  • e.g., intput can be based on DTMF
• Is widely implemented and used (often as one package with Speech recognition and generation)

Web services…

Web Services

• Providers expose “active” (processing) services on the Web
  • documents are transferred to these services for processing
  • results may be returned as documents, too
• Defines a document oriented distributed computing model
• Reminiscent of other models, e.g., distributed objects
  • but not the same! E.g., there is no concept for object lifecycle
  • the ubiquitous Web/Internet infrastructure is a key for deployment
• Lots of players (Oasis, Proprietary initiatives, etc.) which is a source of confusion

Web Services at W3C: the foundations

Messaging framework

• SOAP 1.2 provides the core messaging protocol; defines an envelope, a processing and a binding framework
  • represented in abstract via XML Infoset
  • extra processing can be defined via the headers
  • an upgrade from SOAP 1.1
• Means to include binary data (e.g., photos, digitally encoded materials):
  • XML-binary Optimized Packaging (XOP): an alternative serialization of the Infoset with binary content (using MIME)
  • SOAP Message Transmission Optimization Mechanism (MTOM): how to use XOP in a SOAP envelope
• WS-Addressing: adding information like 'From', 'To', 'ReplyTo', etc, to a SOAP message

Describing web services

• Loose coupling: simple tasks are exposed as stand-alone services
• In order to use those services and do useful things:
  • need to describe how to interact with a service: WSDL 2.0
  • need to describe sequences of interactions among a set of services: WS-CDL 1.0

Web Services Description (WSDL2.0)

• Describes the interface of a service
• Based on WSDL1.0, but with lots of improvements (complete HTTP/1.1 and SOAP1.2 support, inheritance, message exchange patterns…)
• Specification is almost ready (planned for a Recommendation in 2006)

WS Choreography

• Need to describe interactions among a set of services: WS-CDL 1.0
  • choreography of services, based on their observable behaviour (based on π-calculus)
  • describes the common observable behaviour of a group of services
  • provides mean to ensure, e.g., deadlock detection of services

(Possible) future activities in WS

• Description of the semantics of a service:
  • service taking an integer as an argument versus…
  • … service using a ISBN number as an argument versus…
  • … service giving the availability of a book identified by an ISBN number
• this should ensure a better cooperation among services
• Internationalization: preferences and configuration information to provide culturally sensitive or multi-lingual operation (with SOAP and WSDL extensions)
• …

Semantic Web…

Problems leading to the Semantic Web…

• Tasks often require to combine data on the Web:
  • hotel and travel infos may come from different sites
  • searches in different digital libraries
  • various databases within an organization (eg, after company mergers)
  • etc.
• Humans combine these information easily, even if different terminologies, terms, languages, etc, are used…
• Machines have real problems with that!

Example: Automatic Airline Reservation

• Your automatic airline reservation
  • knows about your preferences
  • builds up knowledge base using your past
  • can combine the local knowledge with remote services:
    • airline preferences
    • dietary requirements
    • calendaring
    • etc
• It communicates with remote information (i.e., on the Web!)
• (M. Dertouzos: The Unfinished Revolution)

Example: Data(base) Integration

• Databases are very different in structure, in content
• Lots of applications require managing several databases
  • after company mergers
  • combination of administrative data for e-Government
  • biochemical, genetic, pharmaceutical research
  • etc.
• Most of these data are now on the Web (though not necessarily public yet)
• The semantics of the data(bases) should be known (how this semantics is mapped on internal structures is immaterial)

What is needed?

• Data should be available on the Web for further processing by other machines and programs
• Data should be possibly exchanged, merged, combined on a Web scale
• Sometimes, data may describe other data (e.g, using metadata)…
• … but sometimes the data is to be exchanged by itself, like a calendar or travel preferences
• Machines may also need to reason about that data
• The “Semantic Web” is an infrastructure extending the current Web for the interchange and the integration of data on the Web,

What is needed (technically)?

• To make data machine processable, we need:
  • unambiguous names for resources (that may also bind data to real world objects): URI-s
  • a common data model to access, connect, describe the resources: RDF
  • access to that data: SPARQL
  • define common vocabularies, ontologies: RDFS, OWL, SKOS
  • reasoning logics: OWL, Rules (RIF)

RDF Triples

• We said “interchange” and “connection” of data… ie, resources have to be connected
• But a simple connection is not enough… it should be named somehow
  • a connection from me to my calendar is not the same as the connection from me to my CV (even if all of these are on the Web)
  • the first connection should somehow say “myCalendar”', the second “myCV”
• Hence the RDF Triples: a labelled connection between two resources

RDF Triples (cont.)

• An RDF Triple (s,p,o) is such that:
  • “s”, “p” are URI-s, ie, resources on the Web; “o” is a URI or a literal
  • conceptually: “p” conects, or relates the “s” and ”o”
  • note that we use URI-s everywhere for naming: i.e., we can use http://www.example.org/myCalendar
  • here is the complete triple:

(http://www.ivan-herman.net, http://…/myCalendar, http://…/calendar)

• RDF is a general model for such triples
  • … with machine readable formats (RDF/XML, Turtle, n3, RXR, …), where RDF/XML is the “official” format

RDF Triples (cont.)

• RDF Triples are also referred to as “triplets”, or “statement”
• The s, p, o resources are also referred to as “subject”, “predicate”, ”object”, or “subject”, ”property”, ”object”
• Resources can use any URI; i.e., it can denote an element within an XML file on the Web, not only a “full” resource, e.g.:
  • http://www.example.org/file.xml#xpointer(id('calendar'))
  • http://www.example.org/file.html#calendar

RDF is a Graph

• An (s,p,o) triple can be viewed as a labeled edge in a graph
  • i.e., a set of RDF statements is a directed, labeled graph
    • both “objects” and “subjects” are the graph nodes
    • “properties” are the edges
• One should “think” in terms of graphs; XML or Turtle syntax are only the tools for practical usage!
• RDF authoring tools may work with graphs, too (XML or Turtle is done “behind the scenes”)

A Simple RDF Example

<rdf:Description rdf:about="http://.../membership.svg#FullSlide>
    <axsvg:graphicsType>Chart</axsvg:graphicsType>
    <axsvg:labelledBy rdf:resource="http://...#BottomLegend/>
    <axsvg:chartType>Line</axsvg:chartType>
</rdf:Description>

URI-s Play a Fundamental Role

• Anybody can create (meta)data on any resource on the Web
  • e.g., the same SVG file could be annotated through other terms
  • semantics is added to existing Web resources via URI-s
  • URI-s make it possible to link (via properties) data with one another
• URI-s ground RDF into the Web
  • information can be retrieved using existing tools
  • this makes the “Semantic Web”, well… “Semantic Web”

URI-s: Merging

• It becomes easy to merge data
  • e.g., applications may merge the SVG annotations
• Merge can be done because statements refer to the same URI-s
  • nodes with identical URI-s are considered identical
• Merging is a very powerful feature of RDF
  • metadata may be defined by several (independent) parties…
  • …and combined by an application
  • one of the areas where RDF is much handier than pure XML in many applications

What Merge Can Do...

RDF is not Enough…

• Creating data and using it from a program works, provided the program knows what terms to use!
• We used terms like:
  • Chart, LabelledBy, IsAnchor, ...
  • ChartType, GraphicsType, ...
  • etc
• Are they all known? Are they all correct? (it is a bit like defining record types for a database)

Possible Issues to Handle

• What are the possible terms?
  • “is the set of data terms known to the program?”
• Are the properties used correctly?
  • “do they make sense for the resources?”
• Can a program reason about some terms? Eg:
  • “if «A» is left of «B» and «B» is left of «C», is «A» left of «C»?”
  • obviously true for humans, not obvious for a program …
  • … programs should be able to deduce such statements
• If somebody else defines a set of terms: are they the same?
  • clearly an issue in an international context

Ontologies

• The Semantic Web needs a support of ontologies:

“defines the concepts and relationships used to describe and represent an area of knowledge”

• We need a Web Ontologies Language to define:
  • the terminology used in a specific context
  • possible constraints on properties
  • the logical characteristics of properties
  • the equivalence of terms across ontologies
  • etc
• This is done by RDFS (RDF Schemas) and OWL (Web Ontology Language)

The Work is Not Over

Query

a Query Language and Protocol for RDF (SPARQL); almost finished

Rules

more general logical rules to the Semantic Web infrastructure; work has just begun

Trust

a trust infrastructure for SW (for example: “can I trust the author of this set of assertions?”); future stack of W3C…

The Semantic Web layercake…

This is still an evolving structure…

Portals

• Vodafone's Live Mobile Portal
  • search application (e.g. ringtone, game, picture) using RDF
    • page views per download decreased 50%
    • ringtone up 20% in 2 months
• Sun’s SwordFish: public queries for support, handbooks, etc, go through an internal RDF engine for White Paper Collections and System Handbook collections
• Nokia has a somewhat similar support portal

Improved Search via Ontology: GoPubMed

• Improved search on top of pubmed.org
• Search results are ranked using the specialized ontologies
• Extra search terms are generated and terms are highlighted
• Importance of domain specific ontologies for search improvement

Privacy…

Privacy: P3P

• A framework for automated privacy discussions
  • Web sites disclose their privacy practices in standard machine-readable formats
  • Web browsers automatically retrieve P3P privacy policies and compare them to users' privacy preferences
  • Sites and browsers can then negotiate about privacy terms
  • Negotiation postponed until later
• Is a recommendation since April 2002

How P3P works

Security

• W3C has defined the basic building blocks for Security in XML:
  1. Digitally sign XML documents (XML Signatures)
  2. Digitally encrypt/decrypt XML documents, or parts of XML documents (XML Encryption)
  3. Protocols to maintain and exchange keys (Key Management)
• Further work: W3C has just announced a workshop on Web Authentication

The “horizontals”…

The Web is for everybody!

• Regardless of language, culture, geographical location
  • character sets; vertical, left-to-right and right-to-left writings, …
  • format of dates, phone numbers, ZIP codes, numbered or bulleted items, …
  • different keyboard types
  • typographical rules for emphasis, justification, …
• 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, phones, TV-s, PDA-s, …
  • low bandwidth, small B/W screen, no sound, no screen, …

Horizontal Activities at W3C

• W3C has a number of activities to reinforce those principles
  • “horizontal” review of all W3C technologies:
    • internationalization, multimodality, accessibility, device independence, …
    • specification can be “sent back” to the drawing board if problems occur!
  • separate education and outreach activities:
    • tutorials, information for designers, quicktips, guidelines

Example: international text

Leading the Web to its Full Potential…
Duent la Web al seu ple potencial…
Het Web tot zijn volle potentieel ontwikkelen…
Amener le Web vers son plein potentiel…
Alle Möglichkeiten des Web erschließen…
Οδηγώντας τον παγκόμιο ιστό στο μέγιστο των δυνατοτήτων του…
Hogy kihasználhassuk a Web nyújtotta összes lehetőséget…
वेब की सम्पूर्ण क्षमता के उपयोग की दिशा में अग्रणी…
Sviluppare al massimo il potenziale del Web…
引发网络的全部潜能…
웹의 모든 잠재력을 이끌어 내기 위하여…
Levando a Web em direcção ao seu potencial màximo…
Pаскрывая весь потенциал Сети…
Guiando la web hacia su máximo potencial…
Se till att Webben når sin fulla potential…
Ohjaamassa Webin kehittymistä täyteen mittaansa…
Webの可能性を最大限に導き出すために⋮
لإيصال الشبكة المعلوماتية إلىأقصى إمكانياتها…
להוביל את הרשת למיצוי הפוטנציאל שלה…
引發網絡的全部潛能⋮

Results: Over 60 Different Technologies!

What Can You Do to Help W3C?

• Provide your technical comments on all drafts; don’t be shy!
• Be the first to implement a new standard
• Become a supporter of W3C, even a small sum is valuable, or…
• …if you can influence your institution: get it to join W3C as a member!
  • contact the regional office in your country or W3C itself, or mail me: ivan@w3.org

Further Information

These slides are at:

http://www.w3.org/2006/Talks/0208-DelhiIIT-IH/

More information about W3C:

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

Contact the Indian Office:

http://www.w3cindia.in

Mail me:

ivan@w3.org