address@hidden writes:
Then it's a good thing that David shared his code as free (as in
freedom[1]) software, so that it can be modified for your unique use
case.
What's relevant for this is mostly "in source of an interpreted
language", since modifying and using code given to you for your own
private use tends to be allowed by most copyright jurisdiction. The
freedom of the GPL kicks in when you want to _share_ your modifications
with others, for discussion, for integration into LilyPond, or for
other
purposes.
The modified file is attached, and example usage is below.
Well, that kind of thing (_you_ modifying the copy and reposting on the
list) definitely requires the actual freedom of the code.
So what are the original terms? Looking at David's original GitHub
page, I see "MIT license". The terms of the MIT license are quite
permissive but contain
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
which hasn't happened here. So you are in breach of the license and
the
reference to "freedom" is a red herring. What's really involved here
is
that David is a nice guy unlikely to sue people reusing his code and
you
are relying on that. Now of course the _spirit_ of the license is
"feel
free to use it, I don't care" so that assumption is likely pretty good
but that does not save you against David having a really bad day.
And when talking about licenses, really bad days are what they are good
for. A really bad day may involve bankruptcy and all your private
assets being acquired by Microsoft. That kind of thing often involves
a
substantial change of mind of the new copyright owner.
A license, as opposed to relying on people to stay nice, also protects
you against such worst case scenarios.
Also many (but not necessarily all) code pieces from David may be
substantially derived from LilyPond code code licensed under the GPL.
In that case, the derived code cannot be licensed under different
conditions without being, in turn, in violation of the code it made use
of.
Basically, the bulk of our interactions are governed by everyone being
nice, and that's how most programmers interacted with each other half a
century ago. But when push comes to shove and/or the legal department
comes into play and sees purportive company assets being juggled with,
a
license as a fallback may make a difference. The GPL as the legal
basis
for GNU was created after push came to shove regarding Gosling Emacs.
So while we act regarding the letter of the licenses we are working
with
rather intermittently, it turns out that the actual underlying licenses
leave very little substance for legal departments and miffed persons to
get really nasty with rather than mostly annoying.
Not a perfect world, but it's less dangerous to pretend it is than
before we picked licenses.
[1] https://www.gnu.org/philosophy/free-sw.html