Copyleft??????????

Copyleft is a play on the word copyright and is the practice of using copyright law to remove restrictions on distributing copies and modified versions of a work for others and require that the same freedoms be preserved in modified versions.

Copyleft is commonly implemented by a license and is applied to works such as computer

software, documents, music, and art. Whereas copyright law, by default, automatically restricts the right to make and redistribute copies of an author's work, a copyleft license uses copyright law to ensure that every person who receives a copy of a work has the same rights to study, use, modify, and also redistribute both the work, and derived versions of the work. Such licenses typically do so by requiring that the same license terms apply to all redistributed versions of the work. The widest used and originating copyleft license is the GNU General Public License (GPL).

In a non-legal sense, copyleft is the opposite of copyright, by passing on the freedoms of copyright to all recipients of the work. In a legal sense, copyleft uses the right of the author to impose copyright restrictions with a copyright license on those who want to use the work in ways that require copyright. Under a copyleft form of copyright license, the restrictions imposed are that the work can be copied, modified or used in any subsequent work if, and only if, the author of that subsequent work agrees to grant the same copyleft rights to the public to freely copy, use and modify the subsequent work. For this reason copyleft licenses are also known as reciprocal licenses.

Authors use copyleft to allow anyone to use, share and improve the work as a continuing process, disallowing people from sharing derived works with any new restrictions. While copyleft is not a term in law, it is seen by proponents as a legal tool in a political and ideological debate over intellectual work. Some see copyleft as a first step in doing away with any kind of copyright law. Many fans of copyleft media believe that copyleft is a cross between copyright and public domain. In the public domain, the absence of copyleft-like protection leaves software in an unprotected state. Authors who use source code in the public domain can spread and sell binaries without providing the source code. If legal copyright was abolished and no other rights were provided there would be no means for copyleft licenses to exist. The need for copyleft would be diminished in such an environment, as it would become lawful for the community to disassemble and disseminate proprietary software as free software. However, there would be no way to preserve freedoms and rights for others or protect from propagations like software hoarding.