Semantic MediaWiki (SMW) is an extension to

MediaWiki MediaWiki is free and open-source wiki software originally developed by Magnus Manske for use on Wikipedia on January 25, 2002, and further improved by Lee Daniel Crocker,mailarchive:wikipedia-l/2001-August/000382.html, Magnus Manske's announc ...

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 of interrelationships, commonly spatial, between things within a space. A map may be annotated with text and graphics. Like any graphic, a map may be fixed to paper or other durable media, or may be displayed on ...

calendar A calendar is a system of organizing days. This is done by giving names to periods of time, typically days, weeks, months and years. A calendar date, date is the designation of a single and specific day within such a system. A calendar is ...

s 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 The Karlsruhe Institute of Technology (KIT; ) is both a German public university, public research university in Karlsruhe, Baden-Württemberg, and a research center of the Helmholtz Association. KIT was created in 2009 when the University of Ka ...

(later renamed the

Karlsruhe Institute of Technology The Karlsruhe Institute of Technology (KIT; ) is both a German public research university in Karlsruhe, Baden-Württemberg, and a research center of the Helmholtz Association. KIT was created in 2009 when the University of Karlsruhe (), founde ...

). Currently SMW is maintained by an open-source-community on

GitHub GitHub () is a Proprietary software, proprietary developer platform that allows developers to create, store, manage, and share their code. It uses Git to provide distributed version control and GitHub itself provides access control, bug trackin ...

with Jeroen De Dauw as one of the lead maintainers.

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 lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

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

Berlin Berlin ( ; ) is the Capital of Germany, capital and largest city of Germany, by both area and List of cities in Germany by population, population. With 3.7 million inhabitants, it has the List of cities in the European Union by population withi ...

. 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 Metacafe was an Israeli video-sharing website, launched in July 2003. During the mid-2000s it was one of the largest video-sharing websites, though it eventually began to be superseded by YouTube, Vimeo and Dailymotion. On 28 August 2021, the pl ...

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 Engi ...

, 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, the Libreplanet

wiki A wiki ( ) is a form of hypertext publication on the internet which is collaboratively edited and managed by its audience directly through a web browser. A typical wiki contains multiple pages that can either be edited by the public or l ...

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

Pfizer Pfizer Inc. ( ) is an American Multinational corporation, multinational Pharmaceutical industry, pharmaceutical and biotechnology corporation headquartered at The Spiral (New York City), The Spiral in Manhattan, New York City. Founded in 184 ...

, Harvard Pilgrim Health Care, Johnson & Johnson Pharmaceutical Research and Development, the

Pacific Northwest National Laboratory Pacific Northwest National Laboratory (PNNL) is one of the United States Department of Energy national laboratories, managed by the Department of Energy's (DOE) Office of Science. The main campus of the laboratory is in Richland, Washington ...

, the

Metropolitan Museum of Art The Metropolitan Museum of Art, colloquially referred to as the Met, is an Encyclopedic museum, encyclopedic art museum in New York City. By floor area, it is the List of largest museums, third-largest museum in the world and the List of larg ...

NATO The North Atlantic Treaty Organization (NATO ; , OTAN), also called the North Atlantic Alliance, is an intergovernmental organization, intergovernmental Transnationalism, transnational military alliance of 32 Member states of NATO, member s ...

U.S. Department of Defense The United States Department of Defense (DoD, USDOD, or DOD) is an executive department of the U.S. federal government charged with coordinating and supervising the six U.S. armed services: the Army, Navy, Marines, Air Force, Space Force, t ...

, and the International Atomic Energy Agency. SMW has notably gained traction in the health care domain for collaboratively creating bio-medical terminologies and

ontologies In information science, an ontology encompasses a representation, formal naming, and definitions of the categories, properties, and relations between the concepts, data, or entities that pertain to one, many, or all domains of discourse. More ...

. Examples are LexWiki, which is jointly run by the

Mayo Clinic Mayo Clinic () is a Nonprofit organization, private American Academic health science centre, academic Medical centers in the United States, medical center focused on integrated health care, healthcare, Mayo Clinic College of Medicine and Science ...

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 list of specialized agencies of the United Nations, specialized agency of the United Nations which coordinates responses to international public health issues and emergencies. It is headquartered in Gen ...

and

Stanford University Leland Stanford Junior University, commonly referred to as Stanford University, is a Private university, private research university in Stanford, California, United States. It was founded in 1885 by railroad magnate Leland Stanford (the eighth ...

; 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 aut ...

's NeuroLex. Semantic MediaWiki used to be supported on the now-defunct

wiki farm A wiki hosting service, or wiki farm, is a server or an array of servers that offers users tools to simplify the creation and development of individual, independent wikis. Prior to wiki farms, someone who wanted to operate a wiki had to insta ...

Referata, by default.

Fandom A fandom is a subculture composed of Fan (person), fans characterized by a feeling of camaraderie with others who share a common interest. Fans typically are interested in even minor details of the objects of their fandom and spend a significan ...

has previously activated Semantic MediaWiki on user request, but has stopped doing so since upgrading to version 1.19 of MediaWiki; Fandom wikis, 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 tertiary education. The name traces back to Plato's school of philosophy, founded approximately 386 BC at Akademia, a sanctuary of Athena, the go ...

began urging the use of SMW on

Wikipedia Wikipedia is a free content, free Online content, online encyclopedia that is written and maintained by a community of volunteers, known as Wikipedians, through open collaboration and the wiki software MediaWiki. Founded by Jimmy Wales and La ...

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 predefined HTML markup (like HTML classes) created to serve as descriptive and consistent metadata about elements, designating them as representing a certain type of data (such as contact information, geographic coor ...

markup to Wikipedia in 2007. In 2010,

Wikimedia Foundation The Wikimedia Foundation, Inc. (WMF) is an American 501(c)(3) nonprofit organization headquartered in San Francisco, California, and registered there as foundation (United States law), a charitable foundation. It is the host of Wikipedia, th ...

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 h ...

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, are able to use under the CC0 public domain ...

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, its software uses

Wikibase Wikibase is a set of software tools for working with versioned semi-structured data in a central repository. It is based upon JSON instead of the unstructured data of wikitext normally used in MediaWiki. It stores and organizes information that ...

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 interface for viewing the semantic data in a wiki *

Maps A map is a symbolic depiction of interrelationships, commonly spatial, between things within a space. A map may be annotated with text and graphics. Like any graphic, a map may be fixed to paper or other durable media, or may be displayed on ...

- 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 (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

and

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

. 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