Projects

Ted Nelson's hypertext project, begun in 1960, aiming at a 'docuverse' with two-way links and transclusion. Only partial versions have been released.

Douglas Engelbart's oN-Line System at SRI, with hypertext links, a mouse and shared screens; publicly shown on 9 December 1968.

The UN's register of space objects, kept since the early 1960s and, under the 1974 Registration Convention, filled by launching states with each object's designator, launch date and site, basic orbit and function. It depends on states reporting, so it lags and has gaps.

Early geographic information system built for the Government of Canada from the early 1960s to store and analyse the Canada Land Inventory; it ran until the late 1980s.

Thesauri for art and cultural heritage: the Art & Architecture Thesaurus (from 1981), the Thesaurus of Geographic Names and the Union List of Artist Names. Published as linked open data from February 2014 under an open attribution licence.

Long-running project to hand-encode common-sense knowledge as a logical knowledge base, started at MCC and continued by Cycorp.

The EU's multilingual thesaurus of the subjects of its work, maintained by the Publications Office since 1984 in the 24 official languages and more.

T. S. Kelso's service, begun as a bulletin board in 1985, that republishes the US military's satellite catalogue and orbital elements for the public; it is now a non-profit.

Lexical database of English begun in 1985 at Princeton's Cognitive Science Laboratory under George A. Miller: nouns, verbs and adjectives grouped into sets of synonyms linked by relations such as broader and part-of. It became a shared vocabulary for language processing and for knowledge bases such as YAGO.

Apple's programmable card-and-stack application for the Macintosh, written by Bill Atkinson. It put linked, scriptable documents in the hands of ordinary users.

Free ontology editor from Stanford University, widely used to build OWL ontologies.

Hypertext system of documents linked by URLs and served over HTTP, built by Tim Berners-Lee and Robert Cailliau at CERN from 1990.

Database of films, television and the people who make them. It began in October 1990 as fan lists on the rec.arts.movies newsgroup, became a company in 1996 and was bought by Amazon in 1998; its data is proprietary, released only for non-commercial use, yet other databases link to its title and name IDs.

Email and file encryption program released by Phil Zimmermann in 1991. Instead of a central certificate authority, users vouch for each other's keys, the model its 1992 manual named the web of trust.

Database of CD track listings, started by Ti Kan around 1993 and filled by users who believed it would stay free. It was sold in 1998, renamed Gracenote in 2000 and moved to proprietary terms, which provoked the freedb fork and MusicBrainz.

EU directive of 11 March 1996 on the legal protection of databases, which created a separate 'sui generis' right for database makers alongside copyright; it is why open data licences such as ODbL and CC0 also deal with database rights.

Ontology of gene and gene-product functions begun in 1998 by researchers working on fly, mouse and yeast genomes; one of the most used ontologies in biology.

OpenLink Software's database server for SQL and RDF data, used to publish DBpedia and many other Linked Data sets.

Service that links the name authority files of national libraries and merges records for the same person or organization into one cluster. Begun in 1998 by the Library of Congress, the Deutsche Nationalbibliothek and OCLC; it now draws on more than 50 organizations in over 30 countries.

DARPA research programme started in 1999 by Jim Hendler to create machine-readable representations for the Web; its RDF-based DAML language fed directly into OWL.

Open, volunteer-edited database of music metadata, launched in 2000 in reaction to CDDB's enclosure. Its core data has been in the public domain since 2003, and its identifiers anchor the Music Ontology, BBC Music and Wikidata's music items.

User-built database of music releases and marketplace, launched in November 2000; it lists every pressing and edition, with more than 19 million releases by 2026.

Free, collaboratively written online encyclopedia launched on 15 January 2001 and run by the Wikimedia Foundation. Its infoboxes and links are the raw material of DBpedia, YAGO and Wikidata.

W3C programme that ran the Semantic Web standards work from February 2001, replacing the Metadata Activity, until it was subsumed into the broader Data Activity in December 2013.

W3C project of 2001 for shared web annotations: remarks are stored as RDF on separate annotation servers and shown over the page without changing it.

The Internet Archive's public archive of the Web, open since 25 October 2001 and built from crawls going back to 1996; for many dead links and vanished sites it is the only copy left, kept by a nonprofit funded mainly by donations and grants.

Annual research conference of the Semantic Web community, held since 2002 after a 2001 symposium at Stanford.

Database of protein sequences and functions run since 2002 by a consortium of the EBI, SIB and PIR; it publishes its data as RDF with a public SPARQL endpoint.

Social network launched in 2003 that dominated the late 2000s and became where many musicians hosted their songs. In 2019 it confirmed that about 50 million songs uploaded before 2015 were lost in a server migration.

Social bookmarking site founded by Joshua Schachter in 2003, where people saved links under their own tags; with Flickr it gave rise to the term folksonomy.

EU directive of 2003 setting minimum rules for re-using public sector information, which made re-use of government data a legal matter across the EU; revised in 2013 and recast in 2019 as the Open Data Directive.

The US Space Force's website for orbital data on tracked objects, open to registered users since 2004; classified and military objects are withheld or obscured.

Social network launched in February 2004. Its profiles, pages and 'Log in with Facebook' made a Facebook account a de facto identifier for people and organizations, and its Open Graph protocol turned web pages into objects in its own graph.

Fan wiki, started in 2004, that names and catalogues the recurring devices of fiction and links them to the works that use them: a vocabulary of storytelling built entirely by its readers.

Volunteer-made map of the world, started in 2004 because Britain's Ordnance Survey would not release its data under a free licence. Its features carry free-form key=value tags, a folksonomy steered by a wiki, and its data moved to the share-alike ODbL in 2012.

Database of more than 25 million place names, founded in 2005 and published under a Creative Commons attribution licence. Each place has a stable URI that returns a web page or RDF, with links to Wikipedia, which made it the usual place identifier in linked data.

Extension to MediaWiki that lets wiki pages carry typed, queryable data annotations.

Microblogging service launched in 2006, renamed X in 2023. Its usernames serve as identifiers for people and organizations on about 467,000 Wikidata items; it ended free access to its API in February 2023.

Open-source framework, started in 2006 by Doug Cutting and Mike Cafarella, that implemented MapReduce and a distributed file system and made big data processing available outside Google.

Property-graph database queried with the Cypher language; begun as an open-source project in Sweden in 2007, with version 1.0 in 2010.

Collective of biomedical ontology developers who share principles for building interoperable ontologies; it has led the OBO effort since 2007.

US National Security Agency programme, begun in 2007, that collected internet communications from major US companies including Google, Facebook and Apple; disclosed in June 2013 from documents leaked by Edward Snowden.

Knowledge base built at the Max Planck Institute for Informatics that combines facts from Wikipedia with WordNet's taxonomy (later with schema.org's); with DBpedia, one of the first large knowledge bases extracted from Wikipedia.

Project that extracts structured data from Wikipedia infoboxes and publishes it as Linked Data; an early hub of the Linked Open Data cloud.

Collaboratively edited knowledge graph built by Metaweb and bought by Google in 2010. It fed Google's Knowledge Graph, and its data was offered to Wikidata when it closed in 2016.

EU directive of 14 March 2007 requiring member states to publish their environmental spatial data in common, interoperable forms, building a shared European spatial data infrastructure.

Diagram of datasets published as Linked Data and the links between them, first drawn in 2007 with DBpedia at its centre.

Internet Archive project to build 'one web page for every book ever published', begun in 2007 with Aaron Swartz.

The BBC's pages for every programme (from 2007) and every artist (beta from July 2008), each a web page and an RDF description. Artists were keyed on MusicBrainz identifiers and linked to DBpedia, so a public broadcaster built on fan-made data.

Community-built film and television database, started in 2008, whose free API made it the usual open alternative to IMDb for apps.

Google service launched in February 2008 that crawled XFN, FOAF and other public markup to report who links to whom across the Web; retired in April 2012 for lack of use.

European Union portal to the digitised collections of thousands of cultural heritage institutions, launched in November 2008; it aggregates their metadata with the Europeana Data Model and publishes it as Linked Open Data.

Facebook's sign-in for other sites, unveiled as Facebook Connect in July 2008 and generally available from December 2008, which made a Facebook account a login across the Web.

Linked open data about films, built at the University of Toronto and presented in April 2009, with links from its films to DBpedia and other datasets.

Library of Congress Linked Data Service, publishing its authorities and vocabularies at stable URIs; it opened with the Subject Headings in April 2009.

United States government open data portal, launched in May 2009 by federal CIO Vivek Kundra to publish machine-readable datasets from federal agencies.

Google search feature announced in May 2009 that shows ratings, prices and other details in results, read from microformats and RDFa in pages.

The New York Times's release of its subject headings as linked open data, beginning with about 5,000 people's names on 30 October 2009, mapped by hand to DBpedia and Freebase.

Fan-fiction archive run by the Organization for Transformative Works, open since November 2009. Writers tag freely, and volunteer tag wranglers link the tags to canonical ones, a working middle way between taxonomy and folksonomy; it won a Hugo Award in 2019.

Linked data wrapper for TV Tropes, announced in December 2009, that turns the wiki's pages into RDF linking works of fiction to the tropes they use; by November 2010 about 6,000 of its 16,000 items were linked to DBpedia, and users could correct the extraction.

Approach the BBC used for its 2010 World Cup site: journalists' tags stored in an RDF triplestore against a football ontology and queried with SPARQL to build pages automatically.

UK government open data portal, built under Tim Berners-Lee and Nigel Shadbolt and publicly launched in January 2010.

The UK's official online statute book, run by The National Archives and launched in 2010, which publishes every law as a web page and as data, with each page's data a URI suffix away, and exposes the statute book as linked data.

Community, started with the first IndieWebCamp in 2011, of people who publish on their own domains and connect sites with open standards such as microformats and Webmention, instead of relying on platforms.

Project that extracts microdata, RDFa, JSON-LD and microformats data from the Common Crawl web corpus and publishes it for research.

Google's knowledge base of entities and their relations, launched in 2012 and built partly from Freebase.

Free, collaboratively edited knowledge graph run by the Wikimedia Foundation. It supplies structured data to Wikipedia and the sameAs links on this site.

Permanent URL redirect service run by the W3C Permanent Identifier Community Group since 2013. Anyone can claim a path by pull request and point it wherever their data lives; a consortium of organisations has pledged to keep it running.

Proprietary system, launched in July 2013, that names every 3-metre square on Earth with three words. Widely adopted by British emergency services, it is criticised for its closed, patented algorithm, takedowns of reimplementations and addresses that are easily confused.

Broader W3C programme on data on the Web that took over the Semantic Web Activity's groups in December 2013.

Series of design workshops on decentralised identity and trust, started by Christopher Allen in 2015, whose collaboratively written papers fed into DIDs and Verifiable Credentials. The twelfth was held in Cologne in September 2023; the thirteenth, planned for October 2024, was cancelled for lack of support, and the papers now survive on GitHub.

Tim Berners-Lee's project for storing personal data in user-controlled 'pods' that apps read and write through Linked Data standards.

Peer-to-peer system for storing and sharing files addressed by their content hash, created by Juan Benet; the alpha was released in February 2015.

Public SPARQL endpoint for Wikidata, run by the Wikimedia Foundation since 2015. In May 2025 it moved scholarly articles into a separate graph because its Blazegraph backend could no longer keep up with Wikidata's size.

EU regulation on personal data, adopted on 14 April 2016 and applied from 25 May 2018, which gives people rights over data about them and binds anyone processing it; it set off machine-readable work on consent and data-processing records.

Community of the people, projects and protocols building a decentralized web. It grew out of Brewster Kahle's 2015 call to 'lock the Web open': the Internet Archive held Decentralized Web Summits in 2016 and 2018, then DWeb Camp from 2019, with local nodes in cities worldwide.

Search engine for datasets that indexes schema.org Dataset descriptions published on the Web.

Decentralised social network built on AT Protocol. It began in 2019 as a research initiative announced by Jack Dorsey at Twitter and became independent in 2021.

EU scheme under the 2024 Ecodesign Regulation giving products a digital record of what they are made of and how to repair and recycle them, reached through a QR code; batteries are first, from February 2027, and an EU registry opened in July 2026.

The US Office of Space Commerce's civil service for space situational awareness, which began sending collision warnings to beta users through Space-Track in September 2024; it moves basic space-traffic data from the military to a civil agency.

Open gazetteer of ancient places, built from the Barrington Atlas of the Greek and Roman World by NYU's Institute for the Study of the Ancient World and the Ancient World Mapping Center; each place has a stable URI, and its data is CC BY.