[Haskell-cafe] Dual-licensing the package on Hackage

Vo Minh Thu noteed at gmail.com
Tue Jul 30 11:57:48 CEST 2013

Unless you want to provide multiple open source licenses, I don't see the point:

Anybody that needs a commercial license (and has some money) will
simply ask for such a commercial license when seeing that the code is
available under GPL.

Another reason it is pointless is that you will certainly not want to
list all the commercial licenses you have used/will use with different
clients (there are virtually infinite commercial licenses that you can
invent as needs arise: per seat, per core, per year, and so on
depending on the clients/projects).

I.e. you don't need to state upfront that commercial licences exist
(although I understand that you think it is better to advertise your
willingness to provide such commercial license, but a comment is
enough, the fact is that license is not provided through Hackage).

2013/7/30 Krzysztof Skrzętnicki <gtener at gmail.com>:
> Perhaps it would be best if .cabal allowed to have more than one license
> listed.
> Another solution would be to use custom field, for example:
> License: GPL
> x-Other-License: Commercial, see License-Commercial.txt
> All best,
> Krzysztof Skrzętnicki
> On Tue, Jul 30, 2013 at 11:44 AM, David Sorokin <david.sorokin at gmail.com>
> wrote:
>> Thanks Thu,
>> I agree with you. Just I don't know what to write in the license field of
>> the .cabal file: GPL or OtherLicense. The both choices seem correct to me
>> and misleading at the same time.
>> Cheers,
>> David
>> 30.07.2013, в 12:53, Vo Minh Thu написал(а):
>> > 2013/7/30 David Sorokin <david.sorokin at gmail.com>:
>> >> Hi, Cafe!
>> >>
>> >> Probably, it was asked before but I could not find an answer with help
>> >> of Google.
>> >>
>> >> I have a library which is hosted on Hackage. The library is licensed
>> >> under BSD3. It is a very specialized library for a small target group. Now
>> >> I'm going to relicense it and release a new version already under the
>> >> dual-license: GPLv3 and commercial. In most cases GPL will be sufficient as
>> >> this is not a library in common sense.
>> >>
>> >> Can I specify the GPL license in the .cabal file, or should I write
>> >> OtherLicense?
>> >>
>> >> I'm going to add the information about dual-licensing in the
>> >> description section of the .cabal file, though.
>> >
>> > Although you can indeed license your software under different
>> > licences, in the case of your question it doesn't seem to be a concern
>> > with Hackage:
>> >
>> > The license displayed on Hackage is the one for the corresponding
>> > .cabal file (or at least I think it is). So you issue your new version
>> > with the changed license, the new version is available with the new
>> > license, the old versions are still available with the old license.
>> > Everything is fine.
>> >
>> > Now about the dual licensing. It seems it is again not a problem with
>> > Hackage: you are not granting through Hackage such a commercial
>> > license. I guess you provide it upon request (for some money). I.e.
>> > when I download your library from Hackage, I receive it under the
>> > terms of the BSD (or GPL) license you have chosen, not under a
>> > commercial license that I would have to receive through other means.
>> >
>> > Otherwise the semantic of the license field on Hackage would mean the
>> > library is available under such and such licenses, which are not
>> > granted to you when you download the library on Hackage. Only when you
>> > download the package you can actually find the licensing terms (e.g.
>> > in the LICENSE file). But this seems unlikely to me.
>> >
>> > Cheers,
>> > Thu
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