Don Armstrong wrote:
On Wed, 18 Aug 2004, Måns Rullgård wrote:Nobody has ever tried to extend the copyright of a program toinclude output produced when running the program.If no one has tried, it's because it's quite trivial to contruct a case where a program's output is copyrightable and covered by the copyright of the program. Consider a script that calls imagemagick to create an copyrightable image steming entirely from information contained in the script. Or a LaTeX "program" for that matter. Don Armstrong
I think Bison is a good example here:The parts of the output that are copied from Bison's source code remain part of Bison, and are licensed under Bison's license.
The parts of the output that are derived from the input are a mechanically transformed version of the input, and thus have the same copyright and license as the input.*
Together, the combined work must satisfy both licenses; With the parts from Bison taken out, the work is the input, albeit mechanically transformed.
* (Non-creative transformations do not create derived works - a uuencoded, tarred, etc. version of a work is not derived from the work, it /is/ the work.)
GNU seems to be very much of the opinion that transformations of the source code are copyrightable, while output that depends on the input is not: http://www.gnu.org/licenses/gpl-faq.html#CanIUseGPLToolsForNF
It might also be worth noting that proprietary applications such as Microsoft Office don't use copyright to restrict 'public performance' of the program, instead relying on an EULA (http://download.microsoft.com/download/1/2/5/12538ba0-3d24-4f00-aab1-dd9ff4aacfc9/en_client_eula.pdf).
-- Lewis Jardine IANAL IANADD