The knowledge commons is a commons which encompasses immaterial and collectively owned goods in the information age. Normatively loaded, it promotes free share of knowledge. Since the modern commons' resource is information, the tragedy of the commons has no effect within the knowledge commons—information does not depreciate when being shared with others. In 2012, the concept was discussed at the First Thematic Conference on the Knowledge Commons by the International Association for the Study of the Commons.
The term 'commons' is being derived from the medieval economic system the commons. Today, the knowledge commons act as a frame of reference for a number of domains, including Open Educational resources such as the MIT OpenCourseware, free digital media such as wikipedia, creative commons licensed art, open source research  and open scientific collections such as the Public Library of Science or the Science Commons, Free Software and Open Design. According to research by Charlotte Hess and Elinor Ostrom, the conceptual background of the knowledge commons encompasses two intellectual histories: First, a European tradition of battling the enclosure of the "intangible commons of the mind", threatened by expanding intellectual property rights and privatization of knowledge. Second, a tradition rooted in the United States, which sees the knowledge commons as a shared space allowing for free speech and democratic practices, and which is in the tradition of the town commons movement and commons-based production of scholarly work, open science, open libraries and collective action.
The production of works in the knowledge commons is often driven by collective intelligence respectively the wisdom of crowds and is related to knowledge communism as it was defined by Robert K. Merton, according to whom scientists give up intellectual property rights in exchange for recognition and esteem.
A main principle of the knowledge commons is that the traditional "copyright" is being replaced by "copyleft". For using a work under copyleft, no permission is required and no license has to be acquired; it grants all necessary rights such as right to study, use, remix and redistribute an improved work again—under the only condition that all future works building on the license are again kept in the commons. The most popular applications of the 'copyleft' principle are the GNU Software Licenses (GPL, LGPL and GFDL by Free Software Foundation) and the share-alike licenses under creative commons.
- Digital commons (economics)
- Information Commons
- Libre knowledge
- Open Knowledge
- Open Content
- Public ownership
- Open Source
- Open source appropriate technology
- Open Design
- Collective Intelligence
- Robert K. Merton
- Creative Commons
- Commons-based peer production
- Joshua M. Pearce, “Open Source Research in Sustainability”, Sustainability: the Journal of Record, 5(4), pp. 238-243, 2012. DOI free and open access
- Hess, Charlotte; Ostrom, Elinor (2007). Understanding Knowledge as a Commons - From Theory to Practice. Cambridge: Massachusetts Institute of Technology. pp. 12–13. ISBN 978-0-262-08357-7.
- Boyle, James (2003). "The Second Enclosure Movement and the Construction of the Public Domain". Law and Contemporary Problems 66 (1-2): 33–74.
- Understanding Knowledge as a Commons
- From Digital Libraries to Knowledge Commons
- Open Knowledge Commons - “Shared Purpose. Global Access. Common Knowledge.”
- Imagining A Traditional Knowledge Commons: A * community approach to sharing traditional knowledge for non-commercial research
- First Thematic Conference on the Knowledge Commons held in 2012 on the theme of "Governing Pooled Knowledge Resources: Building Institutions for Sustainable Scientific, Cultural and Genetic Resource Commons"