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Wednesday, March 11, 2015

Semantic Web



From Wikipedia, the free encyclopedia


W3C Semantic Web logo

The Semantic Web is an extension of the Web through standards by the World Wide Web Consortium (W3C).[1] The standards promote common data formats and exchange protocols on the Web, most fundamentally the Resource Description Framework (RDF).[2]

According to the W3C, "The Semantic Web provides a common framework that allows data to be shared and reused across application, enterprise, and community boundaries".[2] The term was coined by Tim Berners-Lee for a web of data that can be processed by machines.[3] While its critics have questioned its feasibility, proponents argue that applications in industry, biology and human sciences research have already proven the validity of the original concept.[4]

The 2001 Scientific American article by Berners-Lee, Hendler, and Lassila described an expected evolution of the existing Web to a Semantic Web.[5] In 2006, Berners-Lee and colleagues stated that: "This simple idea...remains largely unrealized".[6] In 2013, more than four million Webdomains contained Semantic Web markup.[7]

Example

In the following example, the text 'Paul Schuster was born in Dresden' on a Website will be annotated, connecting a person with its place of birth. The following HTML-fragment shows, how a small graph is being described, in RDFa-syntax using schema.org vocabulary and a Wikidata ID:
 
<div vocab="http://schema.org/" typeof="Person">
  ="name">
Paul Schuster</span> was born in <span property="birthPlace" typeof="Place" href="http://www.wikidata.org/entity/Q1731"> <span property="name">Dresden</span>. </span> </div>

Graph resulting from the RDFa example

The example defines the following five triples (shown in Turtle Syntax). Each triple represents one edge in the resulting graph: the first element of the triple (the subject) is the name of the node where the edge starts, the second element (the predicate) the type of the edge, and the last and third element (the object) either the name of the node where the edge ends or a literal value (e.g. a text, a number, etc.).
 
  .
; "Paul Schuster" .
  .
   .
  "Dresden" .

The triples result in the graph shown in the given Figure.

History

The concept of the Semantic Network Model was formed in the early 1960s by the cognitive scientist Allan M. Collins, linguist M. Ross Quillian and psychologist Elizabeth F. Loftus in various publications,[8][9][10][11][12] as a form to represent semantically structured knowledge. When applied in the context of the modern internet, it extends the network of hyperlinked human-readable web pages by inserting machine-readable metadata about pages and how they are related to each other. This enables automated agents to access the Web more intelligently and perform more tasks on behalf of users. The term "Semantic Web" was coined by Tim Berners-Lee,[3] the inventor of the World Wide Web and director of the World Wide Web Consortium ("W3C"), which oversees the development of proposed Semantic Web standards. He defines the Semantic Web as "a web of data that can be processed directly and indirectly by machines".

Many of the technologies proposed by the W3C already existed before they were positioned under the W3C umbrella. These are used in various contexts, particularly those dealing with information that encompasses a limited and defined domain, and where sharing data is a common necessity, such as scientific research or data exchange among businesses. In addition, other technologies with similar goals have emerged, such as microformats.

Purpose

The main purpose of the Semantic Web is driving the evolution of the current Web by enabling users to find, share, and combine information more easily. Humans are capable of using the Web to carry out tasks such as finding the German translation for "eight days", reserving a library book, and searching for the lowest price for a DVD. However, machines cannot accomplish all of these tasks without human direction, because web pages are designed to be read by people, not machines. The semantic web is a vision of information that can be readily interpreted by machines, so machines can perform more of the tedious work involved in finding, combining, and acting upon information on the web. It uses metadata as well.

The Semantic Web, as originally envisioned, is a system that enables machines to "understand" and respond to complex human requests based on their meaning. Such an "understanding" requires that the relevant information sources be semantically structured.

Tim Berners-Lee originally expressed the vision of the Semantic Web as follows:
I have a dream for the Web [in which computers] become capable of analyzing all the data on the Web – the content, links, and transactions between people and computers. A "Semantic Web", which makes this possible, has yet to emerge, but when it does, the day-to-day mechanisms of trade, bureaucracy and our daily lives will be handled by machines talking to machines. The "intelligent agents" people have touted for ages will finally materialize.[13]
The Semantic Web is regarded as an integrator across different content, information applications and systems. It has applications in publishing, blogging, and many other areas.

Often the terms "semantics", "metadata", "ontologies", and "Semantic Web" are used inconsistently.
In particular, these terms are used as everyday terminology by researchers and practitioners, spanning a vast landscape of different fields, technologies, concepts and application areas. Furthermore, there is confusion with regard to the current status of the enabling technologies envisioned to realize the Semantic Web. Gerber, Barnard, and Van der Merwe chart the Semantic Web landscape and provide a brief summary of related terms and enabling technologies in a paper.[14] The architectural model proposed by Tim Berners-Lee is used as basis to present a status model that reflects current and emerging technologies.[15]

Limitations of HTML

Many files on a typical computer can also be loosely divided into human readable documents and machine readable data. Documents like mail messages, reports, and brochures are read by humans. Data, like calendars, addressbooks, playlists, and spreadsheets are presented using an application program which lets them be viewed, searched and combined.

Currently, the World Wide Web is based mainly on documents written in Hypertext Markup Language (HTML), a markup convention that is used for coding a body of text interspersed with multimedia objects such as images and interactive forms. Metadata tags provide a method by which computers can categorise the content of web pages, for example:
 
<meta name="keywords" content="computing, computer studies, computer" />
<meta name="description" content="Cheap widgets for sale" />
<meta name="author" content="John Doe" />

With HTML and a tool to render it (perhaps web browser software, perhaps another user agent), one can create and present a page that lists items for sale. The HTML of this catalog page can make simple, document-level assertions such as "this document's title is 'Widget Superstore'", but there is no capability within the HTML itself to assert unambiguously that, for example, item number X586172 is an Acme Gizmo with a retail price of €199, or that it is a consumer product. Rather, HTML can only say that the span of text "X586172" is something that should be positioned near "Acme Gizmo" and "€199", etc. There is no way to say "this is a catalog" or even to establish that "Acme Gizmo" is a kind of title or that "€199" is a price. There is also no way to express that these pieces of information are bound together in describing a discrete item, distinct from other items perhaps listed on the page.

Semantic HTML refers to the traditional HTML practice of markup following intention, rather than specifying layout details directly. For example, the use of <em> denoting "emphasis" rather than , which specifies italics. Layout details are left up to the browser, in combination with Cascading Style Sheets. But this practice falls short of specifying the semantics of objects such as items for sale or prices.

Microformats extend HTML syntax to create machine-readable semantic markup about objects including people, organisations, events and products.[16] Similar initiatives include RDFa, Microdata and Schema.org.

Semantic Web solutions

The Semantic Web takes the solution further. It involves publishing in languages specifically designed for data: Resource Description Framework (RDF), Web Ontology Language (OWL), and Extensible Markup Language (XML). HTML describes documents and the links between them. RDF, OWL, and XML, by contrast, can describe arbitrary things such as people, meetings, or airplane parts.

These technologies are combined in order to provide descriptions that supplement or replace the content of Web documents. Thus, content may manifest itself as descriptive data stored in Web-accessible databases,[17] or as markup within documents (particularly, in Extensible HTML (XHTML) interspersed with XML, or, more often, purely in XML, with layout or rendering cues stored separately). The machine-readable descriptions enable content managers to add meaning to the content, i.e., to describe the structure of the knowledge we have about that content. In this way, a machine can process knowledge itself, instead of text, using processes similar to human deductive reasoning and inference, thereby obtaining more meaningful results and helping computers to perform automated information gathering and research.

An example of a tag that would be used in a non-semantic web page:
 
blog</item>

Encoding similar information in a semantic web page might look like this:
 
 rdf:about="http://example.org/semantic-web/">Semantic Web
>
Tim Berners-Lee calls the resulting network of Linked Data the Giant Global Graph, in contrast to the HTML-based World Wide Web. Berners-Lee posits that if the past was document sharing, the future is data sharing. His answer to the question of "how" provides three points of instruction. One, a URL should point to the data. Two, anyone accessing the URL should get data back. Three, relationships in the data should point to additional URLs with data.

Web 3.0

Tim Berners-Lee has described the semantic web as a component of "Web 3.0".[18]
People keep asking what Web 3.0 is. I think maybe when you've got an overlay of scalable vector graphics – everything rippling and folding and looking misty – on Web 2.0 and access to a semantic Web integrated across a huge space of data, you'll have access to an unbelievable data resource ...
—Tim Berners-Lee, 2006
"Semantic Web" is sometimes used as a synonym for "Web 3.0",[19] though each term's definition varies.

Challenges

Some of the challenges for the Semantic Web include vastness, vagueness, uncertainty, inconsistency, and deceit. Automated reasoning systems will have to deal with all of these issues in order to deliver on the promise of the Semantic Web.
  • Vastness: The World Wide Web contains many billions of pages. The SNOMED CT medical terminology ontology alone contains 370,000 class names, and existing technology has not yet been able to eliminate all semantically duplicated terms. Any automated reasoning system will have to deal with truly huge inputs.
  • Vagueness: These are imprecise concepts like "young" or "tall". This arises from the vagueness of user queries, of concepts represented by content providers, of matching query terms to provider terms and of trying to combine different knowledge bases with overlapping but subtly different concepts. Fuzzy logic is the most common technique for dealing with vagueness.
  • Uncertainty: These are precise concepts with uncertain values. For example, a patient might present a set of symptoms which correspond to a number of different distinct diagnoses each with a different probability. Probabilistic reasoning techniques are generally employed to address uncertainty.
  • Inconsistency: These are logical contradictions which will inevitably arise during the development of large ontologies, and when ontologies from separate sources are combined. Deductive reasoning fails catastrophically when faced with inconsistency, because "anything follows from a contradiction". Defeasible reasoning and paraconsistent reasoning are two techniques which can be employed to deal with inconsistency.
  • Deceit: This is when the producer of the information is intentionally misleading the consumer of the information. Cryptography techniques are currently utilized to alleviate this threat.
This list of challenges is illustrative rather than exhaustive, and it focuses on the challenges to the "unifying logic" and "proof" layers of the Semantic Web. The World Wide Web Consortium (W3C) Incubator Group for Uncertainty Reasoning for the World Wide Web (URW3-XG) final report lumps these problems together under the single heading of "uncertainty". Many of the techniques mentioned here will require extensions to the Web Ontology Language (OWL) for example to annotate conditional probabilities. This is an area of active research.[20]

Standards

Standardization for Semantic Web in the context of Web 3.0 is under the care of W3C.[21]

Components

The term "Semantic Web" is often used more specifically to refer to the formats and technologies that enable it.[2] The collection, structuring and recovery of linked data are enabled by technologies that provide a formal description of concepts, terms, and relationships within a given knowledge domain. These technologies are specified as W3C standards and include:

The Semantic Web Stack.

The Semantic Web Stack illustrates the architecture of the Semantic Web. The functions and relationships of the components can be summarized as follows:[22]
  • XML provides an elemental syntax for content structure within documents, yet associates no semantics with the meaning of the content contained within. XML is not at present a necessary component of Semantic Web technologies in most cases, as alternative syntaxes exists, such as Turtle. Turtle is a de facto standard, but has not been through a formal standardization process.
  • XML Schema is a language for providing and restricting the structure and content of elements contained within XML documents.
  • RDF is a simple language for expressing data models, which refer to objects ("web resources") and their relationships. An RDF-based model can be represented in a variety of syntaxes, e.g., RDF/XML, N3, Turtle, and RDFa.[23] RDF is a fundamental standard of the Semantic Web.[24][25][26]
  • RDF Schema extends RDF and is a vocabulary for describing properties and classes of RDF-based resources, with semantics for generalized-hierarchies of such properties and classes.
  • OWL adds more vocabulary for describing properties and classes: among others, relations between classes (e.g. disjointness), cardinality (e.g. "exactly one"), equality, richer typing of properties, characteristics of properties (e.g. symmetry), and enumerated classes.
  • SPARQL is a protocol and query language for semantic web data sources.
  • RIF is the W3C Rule Interchange Format. It's an XML language for expressing Web rules which computers can execute. RIF provides multiple versions, called dialects. It includes a RIF Basic Logic Dialect (RIF-BLD) and RIF Production Rules Dialect (RIF PRD).

Current state of standardization

Well-established standards:
Not yet fully realized:
  • Unifying Logic and Proof layers
The intent is to enhance the usability and usefulness of the Web and its interconnected resources through:
  • Servers which expose existing data systems using the RDF and SPARQL standards. Many converters to RDF exist from different applications. Relational databases are an important source. The semantic web server attaches to the existing system without affecting its operation.
  • Documents "marked up" with semantic information (an extension of the HTML tags used in today's Web pages to supply information for Web search engines using web crawlers). This could be machine-understandable information about the human-understandable content of the document (such as the creator, title, description, etc.) or it could be purely metadata representing a set of facts (such as resources and services elsewhere on the site). Note that anything that can be identified with a Uniform Resource Identifier (URI) can be described, so the semantic web can reason about animals, people, places, ideas, etc. Semantic markup is often generated automatically, rather than manually.
  • Common metadata vocabularies (ontologies) and maps between vocabularies that allow document creators to know how to mark up their documents so that agents can use the information in the supplied metadata (so that Author in the sense of 'the Author of the page' won't be confused with Author in the sense of a book that is the subject of a book review)
  • Automated agents to perform tasks for users of the semantic web using this data
  • Web-based services (often with agents of their own) to supply information specifically to agents, for example, a Trust service that an agent could ask if some online store has a history of poor service or spamming

Skeptical reactions

Practical feasibility

Critics (e.g., Which Semantic Web?) question the basic feasibility of a complete or even partial fulfillment of the semantic web. Cory Doctorow's critique ("metacrap") is from the perspective of human behavior and personal preferences. For example, people may include spurious metadata into Web pages in an attempt to mislead Semantic Web engines that naively assume the metadata's veracity. This phenomenon was well-known with metatags that fooled the Altavista ranking algorithm into elevating the ranking of certain Web pages: the Google indexing engine specifically looks for such attempts at manipulation. Peter Gärdenfors and Timo Honkela point out that logic-based semantic web technologies cover only a fraction of the relevant phenomena related to semantics.[27][28]

Core, specialized communities and organizations for intra-company projects tended to practically adopt semantic web technologies greater than peripheral and less-specialized communities.[29] The practical constraints toward adoption have appeared less challenging where domain and scope is more limited than that of the general public and the World-Wide Web.[29]

Censorship and privacy

Enthusiasm about the semantic web could be tempered by concerns regarding censorship and privacy. For instance, text-analyzing techniques can now be easily bypassed by using other words, metaphors for instance, or by using images in place of words. An advanced implementation of the semantic web would make it much easier for governments to control the viewing and creation of online information, as this information would be much easier for an automated content-blocking machine to understand. In addition, the issue has also been raised that, with the use of FOAF files and geolocation meta-data, there would be very little anonymity associated with the authorship of articles on things such as a personal blog. Some of these concerns were addressed in the "Policy Aware Web" project[30] and is an active research and development topic.

Doubling output formats

Another criticism of the semantic web is that it would be much more time-consuming to create and publish content because there would need to be two formats for one piece of data: one for human viewing and one for machines.[citation needed] However, many web applications in development are addressing this issue by creating a machine-readable format upon the publishing of data or the request of a machine for such data. The development of microformats has been one reaction to this kind of criticism. Another argument in defense of the feasibility of semantic web is the likely falling price of human intelligence tasks in digital labor markets, such as Amazon's Mechanical Turk.[citation needed]
Specifications such as eRDF and RDFa allow arbitrary RDF data to be embedded in HTML pages. The GRDDL (Gleaning Resource Descriptions from Dialects of Language) mechanism allows existing material (including microformats) to be automatically interpreted as RDF, so publishers only need to use a single format, such as HTML.

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Tim Berners-Lee


From Wikipedia, the free encyclopedia

Sir Tim Berners-Lee
OM, KBE, FRS, FREng, FRSA, DFBCS
Sir Tim Berners-Lee.jpg
Berners-Lee in 2014.
Born Timothy John Berners-Lee
(1955-06-08) 8 June 1955 (age 59)
London, England
Occupation Computer scientist
Employer
Title Professor
Spouse(s) Rosemary Leith
Parent(s) Conway Berners-Lee
Mary Lee Woods
Awards See full list of honours
Website
www.w3.org/People/Berners-Lee

Sir Timothy John "Tim" Berners-Lee, OM, KBE, FRS, FREng, FRSA, DFBCS (born 8 June 1955),[1] also known as TimBL, is an English computer scientist, best known as the inventor of the World Wide Web. He made a proposal for an information management system in March 1989,[2] and he implemented the first successful communication between a Hypertext Transfer Protocol (HTTP) client and server via the Internet sometime around mid-November of that same year.[3][4][5][6][7]
Berners-Lee is the director of the World Wide Web Consortium (W3C), which oversees the Web's continued development. He is also the founder of the World Wide Web Foundation, and is a senior researcher and holder of the Founders Chair at the MIT Computer Science and Artificial Intelligence Laboratory (CSAIL).[8] He is a director of the Web Science Research Initiative (WSRI),[9] and a member of the advisory board of the MIT Center for Collective Intelligence.[10][11]

In 2004, Berners-Lee was knighted by Queen Elizabeth II for his pioneering work.[12][13] In April 2009, he was elected a foreign associate of the United States National Academy of Sciences.[14][15] He was honoured as the "Inventor of the World Wide Web" during the 2012 Summer Olympics opening ceremony, in which he appeared in person, working with a vintage NeXT Computer at the London Olympic Stadium.[16] He tweeted "This is for everyone",[17] which instantly was spelled out in LCD lights attached to the chairs of the 80,000 people in the audience.[16]

Early life

Berners-Lee was born in London, England, United Kingdom (UK),[18] one of four children born to Mary Lee Woods and Conway Berners-Lee. His parents worked on the first commercially-built computer, the Ferranti Mark 1. He attended Sheen Mount Primary School, and then went on to attend south west London's independent Emanuel School from 1969 to 1973.[1][12] A keen trainspotter as a child, he learnt about electronics from tinkering with a model railway.[19] He studied at The Queen's College of the University of Oxford from 1973 to 1976, where he received a first-class degree in physics.[18]

Career


Berners-Lee, 2005

After graduation, Berners-Lee worked as an engineer at the telecommunications company Plessey in Poole, UK.[18] In 1978, he joined D. G. Nash in Ferndown, Dorset, where he helped create type-setting software for printers.[18]

Berners-Lee worked as an independent contractor at CERN from June to December 1980. While there, he proposed a project based on the concept of hypertext, to facilitate sharing and updating information among researchers.[20] To demonstrate, he built a prototype system named ENQUIRE.[21]

After leaving CERN in late 1980, he went to work at John Poole's Image Computer Systems, Ltd, in Bournemouth, England.[22] He ran the company's technical side for three years.[23] The project he worked on was a "real-time remote procedure call" which gave him experience in computer networking.[22] In 1984, he returned to CERN as a fellow.[21]

In 1989, CERN was the largest Internet node in Europe, and Berners-Lee saw an opportunity to join hypertext with the Internet:
"I just had to take the hypertext idea and connect it to the Transmission Control Protocol and domain name system ideas and—ta-da!—the World Wide Web[24] ... Creating the web was really an act of desperation, because the situation without it was very difficult when I was working at CERN later. Most of the technology involved in the web, like the hypertext, like the Internet, multifont text objects, had all been designed already. I just had to put them together. It was a step of generalising, going to a higher level of abstraction, thinking about all the documentation systems out there as being possibly part of a larger imaginary documentation system."[25]
Berners-Lee wrote his proposal in March 1989 and, in 1990, redistributed it. It was then accepted by his manager, Mike Sendall.[26] He used similar ideas to those underlying the ENQUIRE system to create the World Wide Web, for which he designed and built the first Web browser. His software also functioned as an editor (called WorldWideWeb, running on the NeXTSTEP operating system), and the first Web server, CERN HTTPd (short for Hypertext Transfer Protocol daemon).
"Mike Sendall buys a NeXT cube for evaluation, and gives it to Tim [Berners-Lee]. Tim's prototype implementation on NeXTStep is made in the space of a few months, thanks to the qualities of the NeXTStep software development system. This prototype offers WYSIWYG browsing/authoring! Current Web browsers used in "surfing the Internet" are mere passive windows, depriving the user of the possibility to contribute. During some sessions in the CERN cafeteria, Tim and I try to find a catching name for the system. I was determined that the name should not yet again be taken from Greek mythology. Tim proposes "World-Wide Web". I like this very much, except that it is difficult to pronounce in French..." by Robert Cailliau, 2 November 1995.[27]

Berners-Lee using his PowerBook in 2003

The first website built was at CERN within the border of France,[28] and was first put online on 6 August 1991:
Info.cern.ch was the address of the world's first-ever web site and web server, running on a NeXT computer at CERN. The first web page address was http://info.cern.ch/hypertext/WWW/TheProject.html, which centred on information regarding the WWW project. Visitors could learn more about hypertext, technical details for creating their own webpage, and even an explanation on how to search the Web for information. There are no screenshots of this original page and, in any case, changes were made daily to the information available on the page as the WWW project developed. You may find a later copy (1992) on the World Wide Web Consortium website.[29]
It provided an explanation of what the World Wide Web was, and how one could use a browser and set up a web server.[30][31][32][33]

In 1994, Berners-Lee founded the W3C at MIT, which is located in Massachusetts, United States (US). It comprised various companies that were willing to create standards and recommendations to improve the quality of the Web. Berners-Lee made his idea available freely, with no patent and no royalties due. The World Wide Web Consortium decided that its standards should be based on royalty-free technology, so that they could easily be adopted by anyone.[34]

In 2001, Berners-Lee became a patron of the East Dorset Heritage Trust, having previously lived in Colehill in Wimborne, East Dorset, England.[35]

In December 2004, he accepted a chair in Computer Science at the School of Electronics and Computer Science, University of Southampton, England, to work on the Semantic Web.[36][37]

In a Times article in October 2009, Berners-Lee admitted that the initial pair of slashes ("//") in a web address were actually "unnecessary". He told the newspaper that he could easily have designed web addresses not to have the slashes. "There you go, it seemed like a good idea at the time," he said in his lighthearted apology.[38]

Current work


Tim Berners-Lee at the Home Office, London, on 11 March 2010

In June 2009 then British Prime Minister Gordon Brown announced Berners-Lee would work with the UK Government to help make data more open and accessible on the Web, building on the work of the Power of Information Task Force.[39] Berners-Lee and Professor Nigel Shadbolt are the two key figures behind data.gov.uk, a UK Government project to open up almost all data acquired for official purposes for free re-use. Commenting on the opening up of Ordnance Survey data in April 2010 Berners-Lee said that: "The changes signal a wider cultural change in Government based on an assumption that information should be in the public domain unless there is a good reason not to—not the other way around." He went on to say "Greater openness, accountability and transparency in Government will give people greater choice and make it easier for individuals to get more directly involved in issues that matter to them."[40]

In November 2009, Berners-Lee launched the World Wide Web Foundation in order to "Advance the Web to empower humanity by launching transformative programs that build local capacity to leverage the Web as a medium for positive change."[41]

Berners-Lee is one of the pioneer voices in favour of Net Neutrality,[42] and has expressed the view that ISPs should supply "connectivity with no strings attached," and should neither control nor monitor customers' browsing activities without their expressed consent.[43][44] He advocates the idea that net neutrality is a kind of human network right: "Threats to the Internet, such as companies or governments that interfere with or snoop on Internet traffic, compromise basic human network rights."[45]

Berners-Lee joined the board of advisors of start-up State.com, based in London.[46]

As of May 2012, Berners-Lee is President of the Open Data Institute.[47]

Berners-Lee's tweet, "This is for everyone",[17] at the 2012 Summer Olympic Games in London

The Alliance for Affordable Internet (A4AI) was launched in October 2013 and Berners-Lee is leading the coalition of public and private organisations that includes Google, Facebook, Intel and Microsoft. The A4AI seeks to make Internet access more affordable so that access is broadened in the developing world, where only 31% of people are online. Berners-Lee will help to decrease internet access prices so that they fall below the UN Broadband Commission's worldwide target of 5% of monthly income.[48]

Awards and honours


This NeXT Computer was used by Berners-Lee at CERN and became the world's first web server

Berners-Lee has received many awards and honours.

He received a knighthood in 2004 when he was promoted to Knight Commander of the Order of the British Empire (KBE) in the New Year Honours "for services to the global development of the Internet", and was formally invested on 16 July 2004.[12][49] On 13 June 2007, he received the Order of Merit, becoming one of only 24 living members entitled to hold the honour, and to use the post-nominals 'O.M.' after their name.[50] (The Order of Merit is within the personal bestowal of The Queen, and does not require recommendation by ministers or the Prime Minister)

Personal life

Berners-Lee married Nancy, his wife, in 1990, at the Congregational Church in Fairfield, Connecticut.[51]

He splits his time between homes in the UK and US.[52]

Religious views

Berners-Lee was raised as an Anglican, but in his youth, he turned away from religion, and in his adulthood he became a Unitarian Universalist (UU).[53] He has stated: "Like many people, I had a religious upbringing which I rejected as a teenager... Like many people, I came back to religion when we had children".[54] He and his wife wanted to teach spirituality to his children, and after hearing a Unitarian minister and visiting the UU Church, they opted for it.[55] He is an active member of that Church,[56] to which adheres because he perceives it as a tolerant and liberal belief. He has also recognized the value of other faiths, stating: "I believe that much of the philosophy of life associated with many religions is much more sound than the dogma which comes along with it. So I do respect them."[54]

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World Wide Web Consortium



From Wikipedia, the free encyclopedia

World Wide Web Consortium
W3C® Icon.svg
Abbreviation W3C
Motto Leading the Web to Its Full Potential
Formation October 1994
Type Standards organization
Purpose Developing protocols and guidelines that ensure long-term growth for the Web.
Headquarters Massachusetts Institute of Technology
Cambridge, Massachusetts, U.S.
Location
Region served
 Worldwide
Membership
 385 member organizations[2]
Director
 Tim Berners-Lee
Staff
 62
Website www.w3.org

The World Wide Web Consortium (W3C) is the main international standards organization for the World Wide Web (abbreviated WWW or W3).

Founded and currently led by Tim Berners-Lee,[3] the consortium is made up of member organizations which maintain full-time staff for the purpose of working together in the development of standards for the World Wide Web. As of 24 May 2014, the World Wide Web Consortium (W3C) has 385 members.[2]

W3C also engages in education and outreach, develops software and serves as an open forum for discussion about the Web.

History

The World Wide Web Consortium (W3C) was founded by Tim Berners-Lee after he left the European Organization for Nuclear Research (CERN) in October, 1994. It was founded at the Massachusetts Institute of Technology Laboratory for Computer Science (MIT/LCS) with support from the European Commission and the Defense Advanced Research Projects Agency (DARPA),[3] which had pioneered the Internet and its predecessor ARPANET.

W3C tries to enforce compatibility and agreement among industry members in the adoption of new standards defined by the W3C. Incompatible versions of HTML are offered by different vendors, causing inconsistency in how Web pages are displayed. The consortium tries to get all those vendors to implement a set of core principles and components which are chosen by the consortium.

It was originally intended that CERN host the European branch of W3C; however, CERN wished to focus on particle physics, not information technology. In April 1995 the French Institute for Research in Computer Science and Automation (INRIA) became the European host of W3C, with Keio University becoming the Japanese branch in September 1996. Starting in 1997, W3C created regional offices around the world; as of September 2009, it has eighteen World Offices covering Australia, the Benelux countries (Netherlands, Luxembourg, and Belgium), Brazil, China, Finland, Germany, Austria, Greece, Hong Kong, Hungary, India, Israel, Italy, South Korea, Morocco, South Africa, Spain, Sweden, and the United Kingdom and Ireland.[4]

In October 2012, W3C convened a community of large Web players and publishers to establish a MediaWiki wiki that seeks to document open Web standards called WebPlatform and WebPlatform Docs.

Specification Maturation

Sometimes, when a Specification becomes too large, it is split into independent Modules which can mature at their own pace. Subsequent Editions of a Module or Specification are known as Levels, and are denoted by the first integer in the title (e.g. CSS3 = Level 3). Subsequent Revisions on each Level are denoted by an integer following a decimal point (e.g. CSS2.1 = Revision 1).

The W3C Standard Formation Process is defined within the W3C Process Document, outlining Four Maturity Levels that each new Standard or Recommendation must progress through:[5]

Working Draft (WD)

After enough content has been gathered from 'Editor Drafts' and discussion, it may be published as a Working Draft for review by the community. A WD document is the first form of a standard that is publicly available. Commentary by virtually anyone is accepted, though no promises are made with regard to action on any particular element of said commentary.[5]

At this stage, the standard document may likely have significant differences from its final form. As such, any who implement WD standards should be ready to significantly modify their implementations as the standard matures.[5]

Candidate Recommendation (CR)

A candidate recommendation is a version of the standard that is more firm than the WD. At this point, the group responsible for the standard is satisfied that the standard does what is needed of it. The purpose of the CR is to elicit aid from the development community as to how implementable the standard is.[5]

The standard document may change further, but at this point, significant features are mostly locked. The design of those features can still change due to feedback from implementors.[5]

Proposed Recommendation (PR)

A proposed recommendation is the version of the standard that has passed the prior two levels. The users of said standard have had their say, and the implementors of the standard have likewise had a chance at providing input. At this stage, the document has been submitted to the W3C Advisory Council for final approval.[5]

While this step is important, it rarely causes any significant changes to a standard as it passes to the next phase.[5]

Both Candidates and Proposals may enter "Last Call" to signal that any further feedback must be provided expeditiously.

W3C Recommendation (REC)

This is the most mature stage of development. At this point, the standard has undergone extensive review and testing, under both theoretical and practical conditions. The standard is now endorsed by the W3C as a standard, indicating its readiness for deployment within its problem domain, and encouraging more widespread support among implementors and authors.[5]

Recommendations can sometimes be implemented incorrectly, partially, or not at all, but many standards define two or more levels of conformance that developers must follow if they wish to label their product as W3C-compliant.[5]

Later Revisions (WD)(NOTES)

A Recommendation may be updated or extended by separately-published, non-technical Errata or Editor Drafts until enough substantial edits accumulate for producing a new edition or level of the Recommendation. Additionally, the W3C publishes various kinds of informative Notes which are to be used as a reference.[5]

Certification

Unlike the ISOC and other international standards bodies, the W3C does not have a certification program. The W3C has decided, for now, that it is not suitable to start such a program owing to the risk of creating more drawbacks for the community than benefits.[5]

Administration

The Consortium is jointly administered by the MIT Computer Science and Artificial Intelligence Laboratory (CSAIL, located in Stata Center[6]) in the USA, the European Research Consortium for Informatics and Mathematics (ERCIM) (in Sophia Antipolis, France), Keio University (in Japan) and Beihang University (in China). The W3C also has World Offices in sixteen regions around the world. The W3C Offices work with their regional Web communities to promote W3C technologies in local languages, broaden W3C's geographical base, and encourage international participation in W3C Activities.

W3C has a relatively small staff team, around 50–60 worldwide recently (as of 2010).[7] The CEO of W3C as of Dec. 2010 is Jeffrey Jaffe,[8] former CTO of Novell. The majority of standardization work is done by external experts in W3C's various working groups.

Membership

The domain w3.org attracted at least 11 million visitors annually by 2008 according to a Compete.com study.[9]

The Consortium is governed by its membership. The list of members is available to the public.[2] Members include businesses, nonprofit organizations, universities, governmental entities, and individuals.[10]

Membership requirements are transparent except for one requirement. An application for membership must be reviewed and approved by W3C. Many guidelines and requirements are stated in detail, but there is no final guideline about the process or standards by which membership might be finally approved or denied.[11]

The cost of membership is given on a sliding scale, depending on the character of the organization applying and the country in which it is located.[12] Countries are categorized by the World Bank's most recent grouping by GNI ("Gross National Income") per capita.[13]

Criticism

In 2012 and 2013, W3C started considering adding DRM-specific Encrypted Media Extensions (EME) to HTML5, which was criticised as being against the openness, interoperability and vendor-neutrality that distinguished websites built using only W3C standards from those requiring proprietary plug-ins like Flash.[14][15][16][17][18]

Standards

W3C/IETF Standards (over Internet protocol suite):

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