Public domain

The term public domain has two senses of meaning. Anything published is out in the public domain in the sense that it is available to the public. Once published news and information in books is in the public domain, although they may also be copyrighted. In the sense of intellectual property, works in the public domain are those whose exclusive intellectual property rights have expired, have been forfeited, or are inapplicable. For example, the works of Shakespeare and Beethoven, and most of the early silent films, are all now in the public domain by either being created before copyrights existed or leaving the copyright term. Examples for works not covered by copyright which are therefore in the public domain, are the formulae of Newtonian physics, cooking recipes and all software before 1974. Examples for works actively dedicated into public domain by their authors are reference implementations of cryptographic algorithms,NIH's ImageJ, and the CIA's World Factbook. The term is not normally applied to situations where the creator of a work retains residual rights, in which case use of the work is referred to as "under license" or "with permission".

As rights are country-based and vary, a work may be subject to rights in one country and be in the public domain in another. Some rights depend on registrations on a country-by-country basis, and the absence of registration in a particular country, if required, creates public domain status for a work in that country.

Although the term "public domain" did not come into use until the mid-18th century, the concept "can be traced back to the ancient Roman Law, as a preset system included in the property right system." The Romans had a large proprietary rights system where they defined "many things that cannot be privately owned" as res nullius, res communes, res publicae and res universitatis. The term res nullius was defined as things not yet appropriated. The term res communes was defined as "things that could be commonly enjoyed by mankind, such as air, sunlight and ocean." The term res publicae referred to things that were shared by all citizens, and the term res universitatis meant things that were owned by the municipalities of Rome. When looking at the public domain from a historical perspective, one could say the construction of the idea of "public domain" sprouted from the concepts of res communes, res publicae, and res universitatis in early Roman law.

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