Public domain software is software that has been placed in the public domain, in other words there is absolutely no ownership such as copyright, trademark, or patent.
Under the Berne Convention, which most countries have signed, an author automatically obtains the exclusive copyright to anything they have written, and local law may similarly grant copyright, patent, or trademark rights by default. The Berne Convention also covers programs. Therefore, a program is automatically subject to a copyright, and if it is to be placed in the public domain, the author must explicitly disclaim the copyright and other rights on it in some way. In some regions, some rights (in particular moral rights) cannot be disclaimed.
"Public domain" may be used incorrectly to refer to any software distributed under a free software license. Although the software was released under a licence that grants rights to others (such as the freedom to modify and redistribute the software), the copyright (or other rights) to the software may still be held by the author. Therefore such software would not be in the public domain. For clarity, the Free Software Foundation recommends using "public domain" for the strict meaning only, and using other terms like freeware to convey the other meanings. On a related note, an executable program may be in the public domain even if its source code is not made available. This means that public domain software is not necessarily free software, but is freeware.
The term "public domain" may also be used to mean free, as in having no cost (i.e. gratis). However most gratis software is not in the public domain, but simply released under a free software licence that permits distribution of the software so long as no charge is levied. The confusion may arise from 1980s to 1990s software culture, in which "public domain" (usually abbreviated to "PD") software collections were a popular kind of free software in both the "gratis" and "libre" senses of the term.
In the 1980s, a common way to share public domain software was by receiving them through a local user group or a company like PC-SIG, of Sunnyvale, California, who maintained a mail-order catalog of more than 300 disks with an average price of $6(US).
Famous quotes containing the words public and/or domain:
“The only thing that was dispensed free to the old New Bedford whalemen was a Bible. A well-known owner of one of that city’s whaling fleets once described the Bible as the best cheap investment a shipowner could make.”
—For the State of Massachusetts, U.S. public relief program (1935-1943)
“You are the harvest and not the reaper
And of your domain another is the keeper.”
—John Ashbery (b. 1927)