Semantic MediaWiki (SMW) is an extension to

MediaWiki MediaWiki is a free and open-source wiki software. It is used on Wikipedia and almost all other Wikimedia websites, including Wiktionary, Wikimedia Commons and Wikidata; these sites define a large part of the requirement set for MediaWi ...

that allows for annotating semantic data within wiki pages, thus turning a wiki that incorporates the extension into a

semantic wiki A semantic wiki is a wiki that has an underlying model of the knowledge described in its pages. Regular, or syntactic, wikis have structured text and untyped hyperlinks. Semantic wikis, on the other hand, provide the ability to capture or identif ...

. Data that has been

encoded In communications and information processing, code is a system of rules to convert information—such as a letter, word, sound, image, or gesture—into another form, sometimes shortened or secret, for communication through a communication ...

can be used in

semantic search Semantic search denotes search with meaning, as distinguished from lexical search where the search engine looks for literal matches of the query words or variants of them, without understanding the overall meaning of the query. Semantic search seek ...

es, used for aggregation of pages, displayed in formats like

map A map is a symbolic depiction emphasizing relationships between elements of some space, such as objects, regions, or themes. Many maps are static, fixed to paper or some other durable medium, while others are dynamic or interactive. Although ...

s, calendars and graphs, and exported to the outside world via formats like RDF and CSV.

Authors

Semantic MediaWiki was initially created by Markus Krötzsch, Denny Vrandečić and Max Völkel, and was first released in 2005. Its development was initially funded by the EU-funded FP6 project SEKT (CORDIS site), and was later supported in part by Institute AIFB of the University of Karlsruhe (later renamed the Karlsruhe Institute of Technology). Currently James Hong Kong is the lead developer , while the other core developer is Jeroen De Dauw.

Basic syntax

Every semantic annotation within SMW is a "property" connecting the page on which it resides to some other piece of data, either another page or a data value of some type, using triples of the form "subject, predicate, object". As an example, a page about

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

could have, encoded within it, the fact its capital city is

Berlin Berlin ( , ) is the capital and List of cities in Germany by population, largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's List of cities in the European Union by population within ci ...

. On the page "Germany", the syntax would be: ... the capital city is Has capital::Berlin ... which is semantically equivalent to the statement "Germany" "Has capital" "Berlin". In this example the "Germany" page is the ''subject'', "Has capital" is the ''predicate'', and "Berlin" is the ''object'' that the semantic link is pointing to. However, the much more common way of storing data within Semantic MediaWiki is via MediaWiki templates which themselves contain the necessary SMW markup. For this example, the "Germany" page could contain a call to a template called "Country", that looked like this: The "Country" template would handle storing whatever the value of the parameter "Capital" is, using the property "Has capital". The template would also handle the display of the data. Semantic MediaWiki developers have estimated that 99% of SMW data is stored in this way. Semantic MediaWiki also has its own inline querying tools. For instance, if pages about countries stored additional information like population data, a query could be added to a page that displays a list of all countries with a population greater than 50 million, along with their capital city; and Germany would appear in such a list, with Berlin alongside it.

Usage

Semantic MediaWiki is in use on over 1,600 public active wikis around the world, in addition to an unknown number of private wikis. Notable public wikis that use SMW include the Metacafe wiki,

Web Platform The Web platform is a collection of technologies developed as open standards by the World Wide Web Consortium and other standardization bodies such as the Web Hypertext Application Technology Working Group, the Unicode Consortium, the Internet Engin ...

, SNPedia,

SKYbrary SKYbrary is a wiki created by the EUROCONTROL, European Organisation for the Safety of Air Navigation, ICAO, International Civil Aviation Organization, and the Flight Safety Foundation to create a comprehensive source of aviation safety information ...

, Metavid, Familypedia,

OpenEI Open Energy Information (OpenEI) is a website for policy makers, researchers, technology investors, venture capitalists, and market professionals with energy data, information, analyses, tools, images, maps, and other resources. It was establ ...

, the

Libreplanet LibrePlanet (literally, "Free Planet") is a community project created and supported by the Free Software Foundation. Its objective is the promotion of free software around the world by bringing every year an international conference to local comm ...

wiki A wiki ( ) is an online hypertext publication collaboratively edited and managed by its own audience, using a web browser. A typical wiki contains multiple pages for the subjects or scope of the project, and could be either open to the pub ...

, the Free Software Directory and translatewiki.net. Organizations that use SMW internally include

Pfizer Pfizer Inc. ( ) is an American multinational pharmaceutical and biotechnology corporation headquartered on 42nd Street in Manhattan, New York City. The company was established in 1849 in New York by two German entrepreneurs, Charles Pfizer ...

Harvard Pilgrim Health Care Harvard Pilgrim Health Care is a non-profit health services company based in Canton, Massachusetts serving the New England region of the United States. On August 14, 2019, the boards of Harvard Pilgrim Health Care and Tufts Health Plan announced p ...

, Johnson & Johnson Pharmaceutical Research and Development, the Pacific Northwest National Laboratory, the

Metropolitan Museum of Art The Metropolitan Museum of Art of New York City, colloquially "the Met", is the largest art museum in the Americas. Its permanent collection contains over two million works, divided among 17 curatorial departments. The main building at 1000 ...

NATO The North Atlantic Treaty Organization (NATO, ; french: Organisation du traité de l'Atlantique nord, ), also called the North Atlantic Alliance, is an intergovernmental military alliance between 30 member states – 28 European and two No ...

and the

U.S. Department of Defense The United States Department of Defense (DoD, USDOD or DOD) is an executive branch department of the federal government charged with coordinating and supervising all agencies and functions of the government directly related to national secur ...

. SMW has notably gained traction in the health care domain for collaboratively creating bio-medical terminologies and ontologies. Examples are LexWiki, which is jointly run by the Mayo Clinic,

National Cancer Institute The National Cancer Institute (NCI) coordinates the United States National Cancer Program and is part of the National Institutes of Health (NIH), which is one of eleven agencies that are part of the U.S. Department of Health and Human Services. ...

World Health Organization The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level of ...

and Stanford University; and

Neuroscience Information Framework The Neuroscience Information Framework is a repository of global neuroscience web resources, including experimental, clinical, and translational neuroscience databases, knowledge bases, atlases, and genetic/genomic resources and provides many auth ...

's NeuroLex. Semantic MediaWiki is also supported on the wiki farm Referata, by default.

Wikia Fandom (formerly known as Wikicities before 2007 and later Wikia before 2019) is a wiki hosting service that hosts wikis mainly on entertainment topics (i.e. video games, TV series, movies, entertainers, etc.). Its domain is operated by Fandom, ...

has previously activated Semantic MediaWiki on user request, but has stopped doing so since upgrading to version 1.19 of MediaWiki; Wikia sites, such as Familypedia, that had started using it are able to continue.

Semantic MediaWiki and Wikidata

Some members of the

academic community An academy (Attic Greek: Ἀκαδήμεια; Koine Greek Ἀκαδημία) is an institution of secondary or tertiary higher learning (and generally also research or honorary membership). The name traces back to Plato's school of philosophy, f ...

began urging the use of SMW on

Wikipedia Wikipedia is a multilingual free online encyclopedia written and maintained by a community of volunteers, known as Wikipedians, through open collaboration and using a wiki-based editing system. Wikipedia is the largest and most-read refer ...

since it was first proposed. In a 2006 paper, Max Völkel ''et al.'' wrote that in spite of Wikipedia's utility, "its contents are barely machine-interpretable. Structural knowledge, e.g. about how concepts are interrelated, can neither be formally stated nor automatically processed. Also the wealth of numerical data is only available as plain text and thus can not be processed by its actual meaning." The Wikimedia community began adding semantic

microformat Microformats (μF) are a set of defined HTML classes created to serve as consistent and descriptive metadata about an element, designating it as representing a certain type of data (such as contact information, geographic coordinates, events ...

markup to Wikipedia in 2007. In 2010,

Wikimedia Foundation The Wikimedia Foundation, Inc., or Wikimedia for short and abbreviated as WMF, is an American 501(c)(3) nonprofit organization headquartered in San Francisco, California and registered as a charitable foundation under local laws. Best know ...

Deputy Director

Erik Möller Erik Möller (born 1979) is a German freelance journalist, software developer, author, and former deputy director of the Wikimedia Foundation (WMF), based in San Francisco. Möller additionally works as a web designer and previously managed hi ...

stated that Wikimedia was interested in adding semantic capabilities to Wikipedia, but that they were unsure whether Semantic MediaWiki was the right solution, since it was unclear whether it could be used without negatively affecting Wikipedia's performance. In April 2012, the Wikimedia Foundation project

Wikidata Wikidata is a collaboratively edited multilingual knowledge graph hosted by the Wikimedia Foundation. It is a common source of open data that Wikimedia projects such as Wikipedia, and anyone else, can use under the CC0 public domain license ...

began, which provides a massive shared database for use in articles of every language in Wikipedia, and other Wikimedia projects. Its content is also freely available to anyone else. Wikidata supplants the potential use of Semantic MediaWiki on Wikipedia, but its software uses

Wikibase Wikibase is a set of MediaWiki extensions for working with versioned semi-structured data in a central repository based upon JSON instead of the unstructured data of MediaWiki wikitext. Its primary components are the ''Wikibase Repository'', an ...

Spinoff extensions

A variety of open-source MediaWiki extensions exist that use the data structure provided by Semantic MediaWiki. Among the most notable are: * Page Forms - enables user-created forms for adding and editing pages that use semantic data * Semantic Result Formats - provides a large number of display formats for semantic data, including charts, graphs, calendars and mathematical functions * Semantic Drilldown - provides a

faceted browser Faceted search is a technique that involves augmenting traditional search techniques with a faceted navigation system, allowing users to narrow down search results by applying multiple filters based on faceted classification of the items. It is som ...

interface for viewing the semantic data in a wiki *

Maps A map is a symbolic depiction emphasizing relationships between elements of some space, such as objects, regions, or themes. Many maps are static, fixed to paper or some other durable medium, while others are dynamic or interactive. Although ...

- displays geographic semantic data using various mapping services

Community

The official gathering for Semantic MediaWiki developers and users is SMWCon, which has been held twice a year since 2010, in various cities in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

and

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...

. The largest such event, in October 2013 in Berlin, had around 90 attendees. The first virtual SMWCon 2020 attracted 234 attendees.

References

External links

* {{Semantic Web Semantic wiki software MediaWiki extensions