Re: GPL question

[Richard Tobin]

In article <85fy5w2y70.fsf@lola.goethe.zz>, David Kastrup  <dak@gnu.org> wrote:

>> This is interesting, because as I understand it the FSF claims that if
>> I distribute code that only works with their libraries (because I use
>> their interfaces), then I must distribute my code under the GPL even
>> if I don't distribute their libraries.

>What _is_ restricted is the distribution of a binary that links the
>different codes: that is no longer a "mere aggregation" or an
>independent work.  It is derivative work.
>
>So you say: "Big deal, I won't link it then.  The customer has to do
>it".  Now if the only conceivable use of the software _is_ to link it
>to a free version of the software, the linking is an integral part of
>the whole activity, and the customer does the linking _on_ _behalf_ of
>the software producer, in order to complete the deal.  Since the
>customer is acting on behalf of the producer, it does not actually
>matter that the producer does not himself do the assembly: he is still
>responsible for it.

The case I am thinking of did indeed involve readline.  The program
was (IIRC) distributed as source but not under the GPL (probably under
a non-commercial or educational licence), and the author added an
optional readline interface.

It seems far from clear that what was distributed constituted a
derivative work - has there been a test case?  It seems quite plausible
that it's the customer who creates the derivative work when he builds
the system with readline.  Otherwise, surely any program written to
use a Windows-specific API would be a derivative work of Windows.

Is Aquamacs a derivative work of MacOS X?  As far as I know, there is
no alternative implementation of Apple's user interface libraries.

This theory would also mean that whether something is a derivative
work can be changed by the actions of an independent third party.

-- Richard
-- 
"Consideration shall be given to the need for as many as 32 characters
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