[The following is my analysis, IANAL.]
On Thu, 2011-06-02 at 00:45 -0400, Richard Fontana wrote:
It is well understood in GPL culture that the original licensor of a
program is not bound by the "no further restrictions"
rule. Nevertheless, the use of a GPL-family license along with a
non-customary additional restriction violates GPL licensing norms, and
arguably creates fatal confusion for downstream distributors.
To be a little more specific, putting aside the provision of GPLv3 that
allows removal of additional restrictions (which seems a little
dangerous), there are two possible interpretations in this situation:
1. The license to distribute granted by the GPL is unusable because
distributors are unable to meet the copyleft condition that they convey
the work under the GPL. (They can only convey it under the GPL as
modified by the additional restriction.)
2. The original licensor intends to create a modified version of the GPL
in which the copyleft condition refers to the modified license. In this
case, the license may be free but it is GPL-incompatible: someone who
combined the work with a second work under the plain GPL would be unable
to convey the result under the GPL as required by the second work.
#2 is something the licensor is entitled to do. If the licensor states
this intent explicitly, I believe such a modified license should be
considered on the same basis as any other new license, and not rejected
out of hand because its construction as the GPL plus a restriction
"violates GPL licensing norms". But just listing GPL and an additional
restriction creates a great deal of confusion. I would treat this like
any other case of unclear licensing in which Fedora demands an official
clarification from upstream before accepting a package.
Let's assume that the "producer line" is some kind of
attribution. What 7(b) is talking about is retention of author
attributions in *source code* of a covered work, or (within limits) in
user interface legal information displays for an interactive
program. It does not authorize requirements to retain functionality
that produces an author attribution in *output*. Moreover, there is
nothing I am aware of in GPLv2 tradition that suggests that similar
terms were ever considered GPL-compatible.
Well, in some cases the output may be a derived work of the program.
For autoconf, it clearly is. For file transformations in general, it
depends on whether the manifestation of the program in the output
reaches the threshold of copyrightability. If the portions of the
program incorporated into the output are nonessential, one could remove
them and the output would no longer be encumbered.
(The one glaring exception to
this is the license of Liberation Fonts; consider that license
grandfathered in unless and until we can ever get that license
What is more galling to me in that case is that the license falsely
refers to 1(b) as an exception, as if to make it seem more benign than
it is. An exception is by definition an additional permission that
distributors are allowed to remove (e.g., in order to combine the work
with a plain-GPL work).