[Haskell-cafe] LGPL and Haskell (Was: Re: ANNOUNCE: tie-knot library)

Thu Dec 13 09:09:18 CET 2012

To take this out of the academic realm and into the real-life realm: I've
actually done projects for companies which have corporate policies
disallowing the usage of any copyleft licenses in their toolset. My use
case was a web application, which would not have been affected by a GPL
library usage since we were not distributing binaries. Nonetheless, those
clients would not have allowed usage of any such libraries. You can argue
whether or not this is a good decision on their part, but I don't think the
companies I interacted with were unique in this regard.

So anyone who's considering selling Haskell-based services to companies
could very well be in a situation where any (L)GPL libraries are
non-starters, regardless of actual legal concerns. This affects the open
source realm as well, because I think many of us want our libraries to be
commercial-friendly (I know this is the case for Yesod).

As one specific data point, I initially created the markdown package[1]
because I couldn't use pandoc[2] in one of these situations due to its GPL
license.

MIchael

[1] http://hackage.haskell.org/package/markdown
[2] http://hackage.haskell.org/package/pandoc

On Thu, Dec 13, 2012 at 10:00 AM, Petr P <petr.mvd at gmail.com> wrote:

>   Hi Felipe,
>
> thanks for making me think about the licenses. Without your suggestion, I
> wouldn't be aware of problems LGPL might cause for Haskell projects. And
> I'm considering the possibility of using BSD (or a similar) license in the
> future.
>
> I'm aware of the issues you pointed out. As you say, since tie-knot is a
> small library, it's not really that important what license it has, it's
> easy to re-implement it if needed. And, until some else contributes to the
> library, anybody can ask me to release the code under a different license,
> if needed.
>
> I'd say that the recent debate was a bit academic. (That wasn't bad at
> all, it clarified many things for me.) Nobody actually said "I want to use
> the library, but I cannot because of the license". Also we're talking about
> LGPL, not GPL, and this makes thing different. Consider this: All packages
> on Hackage have published their source codes. (More than 95% are open
> source, and it's likely that those in "OtherLicence" are too.) With public
> source codes, there is no problem using a LGPL-ed library! Anybody can
> write a BSD licensed program which uses a LGPL library, and because all
> sources are public, the requirement to allow re-linking is easily
> satisfied. And nobody is forced to (L)GPL (unless the library is modified).
> We can freely mix open-source projects that use LGPL and non-copyleft
> licenses. The "LGPL problem" manifests only when someone wants to keep
> source codes secret - then (s)he is forced to solve the problem with
> re-linking. [With GPL, this would be very different, the whole project
> would have to be GPL no matter what.]
>
> I think it would be interesting to make some kind of poll to see what kind
> of software Haskell community writes (FOSS vs closed source) and what
> licensing issues people have. But the usual problem with such polls is that
> only people who have problems vote, so the results are very biased.
>
>   Best regards,
>   Petr
>
>
> 2012/12/12 Felipe Almeida Lessa <felipe.lessa at gmail.com>
>
>> When deciding what license to use, I think one should also think about
>> the role of their library.  For example, containers is quite central
>> to the Haskell community and not easily replaceable.  The tie-knot
>> library, OTOH, may be rewritten from scratch or even just skipped
>> (just tie the knot yourself).  A GPLed containers forces the library
>> user to somehow get a way of complying to the license.  A GPLed
>> tie-knot, OTOH, may be just ignored.
>>
>> What I'm trying to say is that if your library is nice but someone may
>> just rewrite it without much effort, then using GPL will just drive
>> potential users of your library away, which is bad not just for the
>> library but also for those potential users as well.  Perhaps you have
>> a nice library but it may be replaced (with some small pain) by
>> another, similar library.
>>
>> (In particular, I'm not saying that tie-knot is a library that should
>> be ignored.  On the contrary, I think it's quite nice and it would be
>> a shame if I had to ignore it when tying a knot just because of its
>> restrictive license.)
>>
>> Of course, if everything on Hackage was GPLed, then it wouldn't make
>> sense to release something as BSD as you wouldn't be able to use it
>> anyway.  But the reality right now is that we have:
>>
>> ("Apache",3)
>> ("BSD3",3359)
>> ("BSD4",3)
>> ("MIT",269)
>> ("PublicDomain",142)
>>
>> ("GPL",409)
>> ("GPL-2",27)
>> ("GPL-3",147)
>> ("LGPL",138)
>> ("LGPL-2",2)
>> ("LGPL-2.1",25)
>> ("LGPL-3",21)
>>
>> ("OtherLicense",179)
>>
>> This data comes from a quick shell session while considering the
>> latest .cabal of all Hackage packages, so take it with a grain of salt
>> =).
>>
>> Cheers,
>>
>> On Wed, Dec 12, 2012 at 2:12 PM, Jonathan Fischer Friberg
>> <odyssomay at gmail.com> wrote:
>> > +1
>> >
>> > Very similar to my point (see original thread), but put in a better
>> way. :)
>> > As an interesting coincidence, this exact thing happened to someone
>> > just now. (thread "containers license issue")
>> >
>> > Jonathan
>> >
>> > On Wed, Dec 12, 2012 at 5:00 PM, Clark Gaebel <cgaebel at uwaterloo.ca>
>> wrote:
>> >> Since we've already heard from the aggressive (L)GPL side of this
>> "debate",
>> >> I think it's time for someone to provide the opposite opinion.
>> >>
>> >> I write code to help users. However, as a library designer, my users
>> are
>> >> programmers just like me. Writing my Haskell libraries with
>> restrictions
>> >> like the (L)GPL means my users need to jump through hoops to use my
>> >> software, and I personally find that unacceptable. Therefore, I
>> gravitate
>> >> more towards BSD3 and "beer-ware" type licenses. This also means my
>> users
>> >> aren't subjected to my religious views just because they want to use my
>> >> "ones and zeros".
>> >>
>> >> Also, with GHC's aggressive inlining, even if you do have a static
>> linking
>> >> exception in your (L)GPL license, it still may not hold up! Although
>> the
>> >> entire idea is untested in court, GHC can (and will!) inline
>> potentially
>> >> huge parts of statically linked libraries into your code, and this
>> would
>> >> force you to break the license terms if you were to distribute the
>> software
>> >> without source code. In Haskell-land, the GPL is the ultimate in viral
>> >> licensing, and very hard to escape.
>> >>
>> >> That's why I don't use (L)GPL licenses.
>> >>
>> >> Just making sure both sides have a horse in this race :)
>> >>   - Clark
>> >>
>> >>
>> >> On Wed, Dec 12, 2012 at 9:51 AM, kudah <kudahkukarek at gmail.com> wrote:
>> >>>
>> >>> On Wed, 12 Dec 2012 10:06:23 +0100 Petr P <petr.mvd at gmail.com> wrote:
>> >>>
>> >>> > 2012/12/12 David Thomas <davidleothomas at gmail.com>
>> >>> >
>> >>> > Yet another solution would be
>> >>> > what David Thomas suggest: To provide the source code to your users,
>> >>> > but don't allow them to use the code for anything but relinking the
>> >>> > program with a different version of the library (no distribution, no
>> >>> > modification etc.).
>> >>>
>> >>> You can also provide object code for linking, though I'm sure this
>> >>> will not work with Haskell object files. Providing alternative
>> >>> distribution of your program linked dynamically, or a promise to
>> >>> provide one on notice, also satisfies the LGPL as long as
>> >>> dynamic-version is as functional as the static and can be dropped-in
>> >>> as a replacement.
>> >>>
>> >>> _______________________________________________
>> >>> Haskell-Cafe mailing list
>> >>> Haskell-Cafe at haskell.org
>> >>> http://www.haskell.org/mailman/listinfo/haskell-cafe
>> >>
>> >>
>> >>
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>> >
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>>
>>
>> --
>> Felipe.
>>
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>
>
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