public domain

The public domain (PD) consists of all the creative work to which no exclusive intellectual property rights apply. Those rights may have expired, be forfeit, waived or may be inapplicable. Because no one holds the exclusive rights, anyone can legally use or reference those works without permission.

As examples, the works of William Shakespeare, Ludwig van Beethoven, Miguel de Cervantes, Zoroaster, Lao Zi, Confucius, Aristotle, L. Frank Baum, Leonardo da Vinci and Georges Méliès are in the public domain either by virtue of their having been created before copyright existed, or by their copyright term having expired. Some works are not covered by a country's copyright laws, and are therefore in the public domain; for example, in the United States, items excluded from copyright include the formulae of Newtonian physics and cooking recipes. Other works are actively dedicated by their authors to the public domain (see waiver); examples include reference implementations of cryptographic algorithms. The term public domain 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".