Public domain

The term "public domain" (PD) refers to any creative work on which no one has claimed exclusive ownership of the intellectual property rights. It is possible that certain rights are no longer relevant because they have lapsed, been lost, been explicitly relinquished, or are inapplicable. Anyone is free to lawfully use or reference such works in any way they see fit since no one person or entity has the sole rights to them.

It is possible that the works of William Shakespeare, Ludwig van Beethoven, Leonardo da Vinci, and Georges Méliès are in the public domain because they were produced in an era prior to the establishment of copyright laws or because the terms of their copyright protection have since run out. These are just a few examples. Certain works are not protected by the copyright laws of a country and are therefore considered to be in the public domain. In the United States, for instance, the formulae of Newtonian physics, cooking recipes, and all computer software created prior to 1974 are not protected by copyright laws and are therefore considered to be in the public domain. Other works, such as reference implementations of cryptographic methods and the image-processing programme ImageJ, have been voluntarily given to the public domain by their creators (for more information on this practise, see waiver) (created by the National Institutes of Health). It is not common practise to use the phrase "public domain" to circumstances in which the author of a work has certain residual rights; instead, in such circumstances, the use of the work is referred to as being "under licence" or "with permission."

Due to the fact that rights differ from nation to country and jurisdiction to jurisdiction, it is possible for a piece of work to be protected by rights in one country while being in the public domain in another. If a work is not registered in a given nation where registration is necessary, then that work is considered to be in the public domain in that country. Certain rights are dependent on registrations that are conducted on a country-by-country basis. It is possible to use the phrase public domain interchangeably with other terms that are imprecise or ambiguous, such as the public sphere or commons. This includes ideas such as the "commons of the mind," the "intellectual commons," and the "information commons."