from
Jargon File (4.4.4, 14 Aug 2003)
copyleft
/kop'ee.left/, n.
[play on copyright]
1. The copyright notice (`General Public License') carried by {GNU}
{EMACS} and other Free Software Foundation software, granting reuse
and reproduction rights to all comers (but see also {General Public
Virus}).
2. By extension, any copyright notice intended to achieve similar
aims.
from
The Free On-line Dictionary of Computing (8 July 2008)
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}.
[{Jargon File}]
(1995-04-18)