[linux-audio-dev] initial release of libfst - in-process VST support

[Chris Cannam]

On Wednesday 21 Apr 2004 7:40 pm, Paul Davis wrote:
> >Am I completely misreading the thing?  To me, the spirit of the
> > GPL would seem to support that interpretation, i.e. that your
> > source code offer must include everything that a normal person
> > would otherwise lack in order to build your program.
>
> I believe we can work around this by adding an exception to the
> license associated with FST.

I think so too, at least for the case of redistributing libfst.so 
itself.

> Imagine there is a GPL'ed (or LGPL'ed) library that my app uses but
> its not part of the system. I do not have to distribute the source
> to that library as part of my application. I can simply point you
> at the distribution for the library itself. I can tell you "to
> compile this application, you will need libfoo" - this is common
> practice for all GPL'ed applications.

Well, I think strictly speaking this is not true -- I think you would 
indeed have to offer source for the library if asked.  I think it's 
just such common practice when referring to other GPL code that 
everyone accepts it anyway, and since everyone's happy with the 
arrangement, there's no problem.  But I could be totally mistaken.

Also the "system library" provision can be pretty broad -- I remember 
the arguments over whether you could GPL code that used Motif, and I 
don't recall anyone getting in any more than theoretical trouble for 
doing so.  These days you can probably get away with everything that 
comes on the SuSE DVDs.

> [...] I
> think it should be OK to release FST with a license that says "you
> will need these files from Steinberg".
>
> The tricky part of this is that "these files" are not GPL'ed

And don't forget neither is FST, in this scenario, because it has that 
exception in its licence, necessary to make it distributable as a 
library at all.  So I imagine any program that uses it will need the 
same exception.  In effect the situation for any other GPL program is 
just the same as it is for FST itself.

> I take Rosegarden, and add VST-with-FST support to it.
> The current GPL license for Rosegarden *I think* prevents me from
> doing this, because I am aggregating your work with a non-GPL'ed
> work to which I cannot provide the source.

Right.

> You would have to add a
> clause to the license of Rosegarden noting that linkage/aggregation
> with non-GPL'ed code for the purpose of running VST plugins blah
> blah blah.

Right, I agree so far.  Unfortunately my brain really starts to melt 
when I try to consider how this interacts with other GPL libraries 
that Rosegarden also uses, such as the KDE ones.  I suspect it means 
that I can't strictly provide that exception because it would make my 
licence incompatible with the KDE one.  Not that the KDE guys should 
be too bothered, given that for some years they distributed their 
libraries with a dependency on Qt but an incompatible licence to it.

Brrr.


Chris