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

Daniel F difrumin at gmail.com
Tue Jul 30 14:08:21 CEST 2013

I second this.

Also, I would like to point out that the product you get from Hackage
(the source code) will be licensed under the GPL. Nobody can get the
commercial version of the product from Hackage, as one has to contact
you (the owner) directly or in some other manner.

I guess that is what Thu is trying to say.

On Tue, Jul 30, 2013 at 3:03 PM, Vo Minh Thu <noteed at gmail.com> wrote:
> No. If I provide a library to you stating you can use it under the
> term of the GPL3, this does not prevent me from providing it to
> someone else under a different license (provided I have the rights to
> do so, for instance because I am the copyright owner).
> So as far as you're concerned (and this is the case with Hackage in
> this dicussion), the library is provided under the terms of the GPL.
> There is no point saying "but if you pay me I can provide it under
> some other terms".
> 2013/7/30 Jan Stolarek <jan.stolarek at p.lodz.pl>:
>> I'd say "OtherLicense" because:
>>   data License = GPL3
>> is different from
>>   data License = Commercial | GPL3
>> I hope this analogy to Haskell data types is convincing :)
>> Janek
>> ----- Oryginalna wiadomość -----
>> Od: "David Sorokin" <david.sorokin at gmail.com>
>> Do: "Vo Minh Thu" <noteed at gmail.com>
>> DW: "Haskell Cafe" <haskell-cafe at haskell.org>
>> Wysłane: wtorek, 30 lipiec 2013 11:46:00
>> Temat: Re: [Haskell-cafe] Dual-licensing the package on Hackage
>> I am inclined to use value OtherLicense but state in the description
>> that the package is available either under GPL or a commercial license.
>> The latter must be requested to me. Then there would be no required
>> additional steps to use the package under GPL. Only the LICENSE file
>> must be appropriate. Probably, I will need two files LICENSE and
>> LICENSE-GPLv3. In the former I will have add my copyright and write in a
>> simple form that the license is dual and everyone is free to use the
>> library under GPLv3 (which is the main use case) according the terms
>> provided in the corresponded second file.
>> Thanks,
>> David
>> On 30.07.2013 13:57, Vo Minh Thu wrote:
>>> 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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Sincerely yours,
-- Daniil

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