Re: Is it possible to write GPL-Modules for closed-source Software?

[Dave (from the UK)]

Stephan Kuhagen wrote:
> Hello
>
> Subject says it all... I'm working for an Institute/Company which does
> scientific and medical imaging software. We have some OpenSource-Addicts in
> the house (with me as the most addicted...) and try to bring at least some
> of our software to the OpenSource-World. Now there is our
> "Premium"-Software, that will stay closed source for long time (although we
> try our best to convince the others...). If we can not release the software
> under the GPL, we like to release at least some of it's modules under the
> GPL. 
>
> The software does not really need those modules, so it is not dependend on
> them. The modules (there are hundreds of them) are loaded at runtime, not
> statically linked. 
>
> Can I write a module, using the proprietary API of the software and release
> it under the GPL? The GPL-modules would be available as precompiled module
> for Windows/Linux/MacOSX and as source. I like to pack them into the
> commercial installer (including the source of the module, of course) also,
> but this is not required.
>
> Is this possible without violating GPL, or is there no way to "undermine"
> the closed-source-philosophy step-by-step...?
>
> Regards
> Stephan

I'm no expert, but my interpretation is that there is nothing to prevent 
you releasing these modules under the GPL with source code, without you 
making the whole program GPL'ed.

Most commercial operating systems (AIX, IRIX, HP-UX etc) are all closed 
source. But all ship with open-source applications such as the GNU 
project 'wget'

http://www.gnu.org/software/wget/

The source to wget is available, but the source to the operating systems 
is not (Solaris is a partial exception). None of these operating systems 
need wget, but most will include it.

I know of a very nice commercial chess program that runs on a PDA

http://www.pocketgrandmaster.com/english/index.html

which can use open-source chess engines. The chess program ships with 
one engine (closed source module) but can use others.

I don't see anything wrong with what you want to do myself.

BTW, as a half-way house on the rest of the program, could it be 
released as open-source, but not GPL'ed? Sun's Solaris operating system 
is done this way, with most of the source available under a fairly 
restrictive license.

http://www.opensolaris.org/os/

Some of it remains closed source, as Sun are not the copyright owners on 
parts of it - they just license the technology from somewhere else.


--
Dave (from the UK)

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