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Re: [License-review] Chroma license / United States Government Contract



Andreas Cadhalpun <andreas.cadhalpun@googlemail.com> writes:

> Correct me if I am wrong, but I think that if one uses the source of a
> GPL licensed program to build another program, this has to be
> distributed under the GPL as well. (Section 2. b) of the GPL)

That's roughly correct; the act which requires licensing the whole work
under GPL is to distribute a “derivative work” of the prior GPL-licensed
work; see <URL:https://en.wikipedia.org/wiki/Derivative_work>.

The corollary is that if the derived work is not distributed under terms
compatible with the GPL, the recipient has *no* effective license in
the work – and, indeed, the party redistributing has no license to do
so, and is themselves violating the GPL of the prior work.

> If that is true, is it allowed to simply use the chroma source, as if
> the COPYING contained the GPL v2, or is it necessary to contact the
> author of chroma and request a change of the COPYING file?

If their work is derived from a work they received under GPL, then
“chroma” may be redistributed only under GPL-compatible terms (e.g., the
GPL itself), otherwise they are violating copyright on the GPL-licensed
work and “chroma” recipients have no effective license.

-- 
 \       “When I get new information, I change my position. What, sir, |
  `\             do you do with new information?” —John Maynard Keynes |
_o__)                                                                  |
Ben Finney


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