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

Tom Tobin korpios at korpios.com
Wed Dec 9 00:19:47 EST 2009

On Tue, Dec 8, 2009 at 8:19 PM, Robert Greayer <robgreayer at gmail.com> wrote:
> There's another FAQ on GNU site that, I think, addresses the Pandoc/Hakyll
> situation directly:
> http://www.gnu.org/licenses/gpl-faq.html#LinkingWithGPL
> "You have a GPL'ed program that I'd like to link with my code to build a
> proprietary program. Does the fact that I link with your program mean I have
> to GPL my program?
>     Not exactly. It means you must release your program under a license
> compatible with the GPL (more precisely, compatible with one or more GPL
> versions accepted by all the rest of the code in the combination that you
> link). The combination itself is then available under those GPL versions. "

I'll confess to not being sure what exactly this means; this seems to
imply that if you never distribute the GPL'd code itself, you're fine.
 In temporary lieu of posing questions explicitly to the SFLC, I dug
up a copy of _Intellectual Property and Open Source_ by Foobar (and
published by O'Reilly), and found this (from an entire chapter —
Chapter 12 — about the GPL):

"Nevertheless, there is a persistent issue that won’t go away—whether
linking programs together creates a derivative work. If linking
creates a derivative work, the GPL applies to the linked program;
otherwise, the GPL doesn’t apply."
"In legal practice, this arises as a common concern of clients just
getting into open source. This question is usually phrased as either,
'Can I load and use a GPL-licensed library without applying the GPL to
my application?' or, 'Do I have to apply the GPL to my plug-in for a
particular program if that program is licensed under the GPL?'"
"I won’t keep you in suspense; the short answer is that we don’t know."

It then goes on with the "long" answer, which is honestly confusing as
hell.  There's even a question in the FAQ that goes like this:

"Q: That is different than the official GPL FAQ! Why?"

"A: The GPL FAQ was written in inexact language, and gives the
impression that the rules regarding derivative works may have greater
reach than current copyright law allows. The FSF has repeatedly
stated, however, that they believe in copyright minimalism and that
the GPL should not be interpreted to extend beyond the reach of

And the final answer is best:

"Q: Can I depend on the answers in this Q&A to keep me out of trouble?"

"A: No. This is our best understanding of copyright law as it stands
right now, but it could change tomorrow—and nobody really knows until
these questions are resolved in a court of law."

Oh dear Ceiling Cat, I have *no* idea at this point.  Much of the FAQ
deals with distributing *binaries*, though, not source alone.  I'd
still like to get a (somewhat?) straight answer from the SFLC folks,
though.  If it turns out that Hakyll *is* okay to be BSD3 licensed so
long as neither any binary nor the GPL'd work's source is distributed
under non-GPL terms, well ... I'll say that the meaning of "BSD
licensed" will have become much less reliable, since it means you
actually have to trace the genealogy of the libraries you use *all*
the way back in order to understand the situation for certain.

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