Open knowledge

Linked Data published under an open licence. Berners-Lee's 2010 five-star scheme rates open data from 'available in any format' up to 'linked to other data'.

Principles that research data should be findable, accessible, interoperable and reusable, published in Scientific Data in March 2016.

Framework proposed by Creative Commons in June 2025 for dataset holders to state, in machine-readable form, how they want their content reused by AI systems; partly legal and partly a social expectation.

1999 book by Lawrence Lessig on how the Internet is regulated, arguing that software architecture ('code') constrains behaviour much as law, markets and norms do.

Book edited by Charlotte Hess and Elinor Ostrom applying Ostrom's research on how communities sustain shared resources to knowledge: digital libraries, open access, open-source software and the rules that keep them from being depleted or enclosed.

Principles written by thirty open-government advocates meeting in Sebastopol, California, on 7–8 December 2007: government data should be complete, primary, timely, accessible, machine-processable, non-discriminatory, non-proprietary and licence-free.

Nadia Eghbal's 2016 report for the Ford Foundation arguing that open-source software is public infrastructure, maintained by a few unpaid or underpaid people, and that nobody has taken responsibility for funding it.

WWW 2016 paper on moving Freebase's data into Wikidata after Google announced in December 2014 that it would close Freebase: what could be carried over, what could not, and why a company's knowledge base did not simply transfer to a community one.

Open Knowledge Foundation's definition of 'open' for content and data: anyone can freely access, use, modify and share it, subject at most to requirements that preserve provenance and openness. First drafted in 2005.

Creative Commons' RDF vocabulary for describing licences and attaching them to works, written into web pages with RDFa; submitted to the W3C in May 2008.

Creative Commons tool, released in 2009, by which a rightsholder waives all copyright and database rights in a work as far as the law allows, putting it in effect into the public domain. Wikidata's structured data is published under it.

Open Data Commons' copyleft licence for databases: anyone may share, adapt and use a database as long as adapted versions stay open. OpenStreetMap moved to it in 2012.

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.

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.

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.

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.

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.

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.

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

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

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.

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

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

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.

Non-profit digital library in San Francisco that runs the Wayback Machine and Open Library.

Non-profit founded in 2001 that publishes free, standard copyright licences, so creators can grant permissions in advance; the licences come with machine-readable metadata.

Non-profit that hosts Wikipedia, Wikidata and the other Wikimedia projects.

Non-profit that has run MusicBrainz since the end of 2004 and funds it by selling commercial access to its live data feed, while the core data stays in the public domain.

Non-profit founded in Britain in 2004 to promote open knowledge and open data; it maintains the Open Definition and, through Open Data Commons, the Open Database License.

Non-profit registered in England and Wales, set up in April 2006 to support OpenStreetMap; it is funded mostly by donations.

Fan-run non-profit founded in 2007 to preserve fan works and defend them as legitimate; it runs Archive of Our Own and the Fanlore wiki.

London non-profit co-founded by Tim Berners-Lee and Nigel Shadbolt to promote open data.

American private foundation set up by Intel co-founder Gordon Moore and his wife Betty; one of the three funders of Wikidata's initial development in 2012.

American political economist who showed how communities govern shared resources without either state control or privatization; Nobel laureate in economics in 2009.

American businessman who co-founded Alexa Internet with Brewster Kahle and, with him, developed the Wayback Machine.

American legal scholar who co-founded Creative Commons in 2001 and has written on how law and code regulate the Internet.

American internet entrepreneur who co-founded Wikipedia in 2001.

American philosopher who co-founded Wikipedia in 2001 and named it.

American programmer who founded MusicBrainz in 2000 as an open alternative to CDDB, and led it and the MetaBrainz Foundation until his death in 2026.

British economist who co-founded the Open Knowledge Foundation in 2004.

British programmer who started OpenStreetMap in 2004 at University College London.

American programmer and activist who helped write the RSS 1.0 specification as a teenager, led early work on Open Library, and co-founded Reddit.

American librarian and scholar of the knowledge commons, co-editor with Elinor Ostrom of 'Understanding Knowledge as a Commons'.

American publisher of public-domain books online, the plaintiff in Eldred v. Ashcroft, and a co-founder of Creative Commons.

MIT computer scientist, co-author of 'Structure and Interpretation of Computer Programs', who co-founded Creative Commons and co-wrote ccREL.

Dutch science publisher and co-author of 'The Anatomy of a Nanopublication' (2010).

Computer scientist who edited a report on the Scheme language, worked at Science Commons on the CC0 dedication, and on the W3C TAG raised ISSUE-57 and wrote the 2012 call to amend the httpRange-14 resolution.

Creative Commons staff member who co-wrote ccREL (2008); later policy director at GitHub.

American writer on how open-source software is produced and paid for, author of 'Roads and Bridges' (2016) and 'Working in Public' (2020); now publishes as Nadia Asparouhova.

Software engineer at Creative Commons who co-wrote ccREL (2008).

French computer scientist, lead author of 'From Freebase to Wikidata: The Great Migration' (2016).