A question about distributing software under GPL

David Johnson david at usermode.org
Tue Jan 16 06:14:32 UTC 2001

On Monday 15 January 2001 09:11 pm, Chris F Clark wrote:

> If we have some software (a library) that we wish to distibute under
> the GPL, but that software supports an application (specifically an
> application generator) that is not distributed under the GPL and is
> not open source,

The simplest solution is to distribute the library under the LGPL (the 
Library GPL). The is essentially the same as the GPL, but allows non-GPL 
applications to link to it.

>     can we distribute the library under the GPL, and more importantly
>     can we distribute it (and permits others to do so) with the
>     non-open source program, since their interoperability is more than
>     mere aggregation?

As the authors/copyright holders, you can do anything you want! But if this 
library is needed by the generated applications, then please give your 
customers the right to use it. The LGPL does this without restricting what 
license the user may use for their own generated works.

> On a related point, if we cannot distribute our non-open source
> application with a GPL copy of our library, how could anyone release a
> CD with a non-open source Linux application and a copy of Linux (since
> the application is not useful without Linux, of which some parts must
> be GPL)?

Two big reasons why. First of all, using Linux kernel calls is *runtime* 
linkage. The GPL does not restrict this, only static linkage and dynamic 
linkage (there's an occasional disgreement over the latter). Linus Torvalds 
clarifies this with a specific permission in the copyright for Linux. Second, 
most applications distributed on a Linux CD are distributed in aggregate, and 
are in no way derivative of the kernel. The GPL only restricts the original 
and derivative software. -USING- GPL software by non-derivative works is 
expressly permitted. There may be debate over what is a derivative work and 
what is not, but given that 99% of the applications distributed on a Linux CD 
can run just fine under FreeBSD, they can't be derivative of Linux.

> and we recognize that by doing so, we may be opening the
> library up to uses we had never intended, but hey that's a fact of
> life when releasing something as open source.

Oh, if only those who keep submitted faulty licenses to this list in an 
attempt to get them approved understood this...

> Finally, if we can distribute the software as we desire, how should we
> describe it?  We do not intend to call the entire package open source,
> it clearly isn't.  However, we do intend the library to be open
> source.

I wouldn't use the term "Open Source" at all, except in those rare instances 
that the library is distributed by itself. But in the documentation I would 
mention the (L)GPL, and explain how it affects generated applications.

David Johnson

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