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 :

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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 wrote:

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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):

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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

2013/7/30 David Sorokin : 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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