Public domain

When a work is in the public domain, it is free for use by anyone for any purpose. Public domain is the purest form of open/free, since no one owns owns or controls the material in any way. In other words, it is free of any license. For more information, see Wikipedia's article on public domain.

When does a work enter the public domain?

This varies by country. To see when a work in the United States enters the public domain, see copyright.gov's public domain page.

Cornell University has also provided a handy table about copyright term and the public domain in the United States.

Creative Commons Public Domain tools

• CC0 is a waiver that allows copyright holders to place works in the public domain to the extent legally possible, worldwide.
• CC's public domain certification serves to mark works that are in the public domain already. A next-generation version of this tool, to be called a "public domain assertion tool" is under development.

See http://creativecommons.org/publicdomain for more information on CC's public domain tools.