[Haskell-cafe] Re: ANN: hakyll-0.1

Ketil Malde ketil at malde.org
Tue Dec 8 18:41:02 EST 2009

Tom Tobin <korpios at korpios.com> writes:

>>>>> Your contributions could still be licensed under a different license
>>>>> (e.g. BSD), as long as the licensing doesn't prevent somebody else to
>>>>> pick it up and relicense it under GPL.

>>>> Right. So hakyll is absolutely fine with a BSD3 license, AFAICS.

>>> Seriously, no, this is *totally* wrong reading of the GPL, probably
>>> fostered by a misunderstanding of the term "GPL-compatible license".
>>> GPL-compatible means the compatibly-licensed work can be incorporated
>>> into the GPL'd work

You can incorporate all you want, as long as you don't distribute the

>>> If you are forming a derivative work based on the GPL'd
>>> work, and thus you have to release that derivative work under the GPL.

Yes, but I understood the situation to be that Hakyll is using Pandoc as
a library, accessing its API.  If this makes Hakyll a derivative of
Pandoc, then anything running on your Linux box must be GPL, as it uses
system calls (the API of the GPL'ed kernel).

>> available under the GPL (including the hakyll source).  Since the hakyll
>> package is released under BSD3, this would be allowed (AIUI, IANAL).

> IANAL either, but my understanding is that judges take a very dim view
> of attempts like this to evade the requirements of a license.  

I don't consider it an attempt to evade requirements.  For all I know,
the author of Hakyll wrote it using public documentation, and never even
had Pandoc in his possession.  Why should he be bound by its copyright

I've used public specs to write software to parse files generated by
proprietary software.  My code is GPL, and I think it would be
incredibly unreasonable to force me to abide by whatever license the
generating software uses.

> If a piece of software is built on another piece of software, it doesn't
> matter if you're looking at source code or a binary.

The question is if using an API is sufficient to make it a derived work.

> I can write the SFLC and pose a hypothetical situation that captures
> the gist of what we're talking about, and post the response here, if
> anyone is interested.

I'm curious, at least.  If nobody else wants it, feel free to email me

If I haven't seen further, it is by standing in the footprints of giants

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