The public domain consists of works that are…
- no longer in copyright term; or
- were never protected by copyright law.
Public domain works are free to use in any manner without requesting permission.
Works in the public domain are those whose intellectual property rights have expired, have been forfeited, or are inapplicable. Public domain includes works that are unavailable for private ownership or are available for public use. For example, works published before 1923 are in the public domain. Additionally, most U.S. government records are in the public domain and may be freely used.
As rights are country-based and vary, a work may be subject to rights in one country and not in another. Some rights depend on registrations with a country-by-country basis, and the absence of registration in a particular country, if required, implies public domain status in that country.
There are many helpful online resources for determining the public domain or copyright status of a given work. For more information about these resources, please see the links section of this site.
The website, http://www.publicdomainsherpa.com/ is a good resource for determining public domain status in the United States.
The Europeana consortiotium has a Eurozone copyright calculator and resources at http://outofcopyright.eu/
This table published by Peter Hirtle at Cornell is a very thorough and clear set of public domain rules for many types of materials http://copyright.cornell.edu/resources/publicdomain.cfm
The Open Knowledge Foundation maintains a current list of worldwide public domain calculators http://publicdomain.okfn.org/calculators/