[gambit-list] BSD license

Christian Jaeger christian at pflanze.mine.nu
Sat Oct 25 03:58:09 EDT 2008


Arnaud Bergeron wrote:
> 2008/10/24 Marc Feeley <feeley at iro.umontreal.ca>:
>   
>> On 24-Oct-08, at 1:03 PM, Arnaud Bergeron wrote:
>>
>>     
>>> If you are really going the BSD way, then you could just drop the
>>> other two licenses since BSD is compatible with GPL and Apache2.  It
>>> may make things simpler.
>>>       
>> Do you mean they can coexist ("compatible") or the BSD license subsumes GPL
>> (which I'm quite sure is not the case)?
>>     
>
> I mean that if Gambit is licensed only under the BSD (or MIT), then
> anybody who wants to use it with GPL or Apache code can without a dual
> or triple licensing scheme.

I'm not a specialist with licenses. So I'm not sure about further 
implications except for this:

Suppose someone wants to publish his own code based on Gambit (L)GPL so 
that changes to his/her code will have to be republished. Assume Gambit 
itself is only BSD licensed; the combination will contain parts under 
both licenses. Assume to make his own code work, he also had to change 
Gambit in a number of places; would those changes be LGPL or BSD 
licensed? (You can't choose LGPL for the whole Gambit files anymore, 
because the original Gambit code is only licensed under BSD.) Maybe you 
could switch license within the file, i.e. add another license header in 
the midst of the file stating (L)GPL before the new function, but at 
some point this will get impractical, which is why usually such 
contributions are just made under the same license as the existing file, 
right? The only practical solution might be to offer the changes only as 
a patch file, and put the patch under the (L)GPL, but that plays poorly 
with VCS systems etc.

So practically, that someone will have to release the changes to Gambit 
which are not full files under the BSD license. Now if someone else is 
going to take your product (with BSD and (L)GPL parts), and makes 
modifications, he/she is obliged to republish the modifications to the 
(L)GPL parts, but not those to the BSD parts. So he/she is allowed to 
publish sources which won't work (since the republished (L)GPL part may 
not work anymore with the previously published BSD parts).

Also, another (similar) obervation: if some time in the future some 
people would like to create a fork of Gambit which would require 
republishing of changes, i.e. be under the LGPL only, they would be able 
to do so without issue if Gambit is dual/triple licensed; if Gambit is 
BSD only, then they would not be able to do this (without contacting 
each and every contributor to re-publish their code under the LGPL at 
that point, which is usually impractically difficult or almost 
impossible (might require rewrites of code of people who are not 
reachable anymore or refuse to relicense their contributions)).

So I'd say, publishing software also under other licenses than BSD 
grants a user more rights than only publishing under BSD.

Christian.




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