copyleft

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Related to Copy left: Creative Commons

copyleft

(legal)
/kop'ee-left/ (A play on "copyright") The copyright notice and General Public License applying to the works of the Free Software Foundation, granting reuse and reproduction rights to everyone.

Typically copyrights take away freedoms; copyleft preserves them. It is a legal instrument that requires those who pass on a program to include the rights to use, modify, and redistribute the code; the code and the freedoms become legally inseparable.

The copyleft used by the GNU Project combines a regular copyright notice and the "GNU General Public License" (GPL). The GPL is a copying license which basically says that you have the aforementioned freedoms. The license is included in each GNU source code distribution and manual.

See also General Public Virus.

copyleft

A requirement in the GNU GPL software license and other "free" software licenses that anyone who redistributes the software does so under the same license and also includes the source code. The "free" means free of restrictions (see free software). The copyleft clauses were written to support copyright laws, not eliminate them.

Strong Vs. Weak
A "strong copyleft" license, such as the GNU GPL license, applies to all derived works and software components in the package. A "weak copyleft" license, such as the GNU Lesser GPL, applies only to the original copylefted work.

Full Vs. Partial
"Full copyleft" means that all of the work may be modified, whereas "partial copyleft" restricts some parts of the work from being altered. See GNU General Public License and copyright.
References in periodicals archive ?
This software is licensed under the terms of the GNU General Public License Version 2 as published by the Free Software Foundation (GNU General Public License is a free, copy left license for software and other kinds of works).
There's only one copy left, which is in my jukebox at home.
Then she will chat to the shop owner to see whether they need to stock more or less copies - the ideal scenario is having no more than one copy left on the shelf each day.
When I read the story on Thursday morning I had to check the date on the newspaper to make sure I hadn't picked up a copy left over from April Fool's Day.
But a mix-up saw the film copy left in the hold of a plane instead of being hand- delivered by courier.
All inspection/test reports shall have one copy left in the clear plexiglass wall pocket adjacent to the sprinkler system control value or riser of each building being inspected/tested and one copy forwarded to Facilities Managements Office addressed to: Facilities Management Manager 915 SE 5th Street Gainesville FL 32601 2.