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

Chris Cannam cannam at all-day-breakfast.com
Wed Apr 21 18:29:20 UTC 2004

On Wednesday 21 Apr 2004 5:24 pm, Paul Davis wrote:
> This is an error on my part. I forgot that libwinelib.c was covered
> by an LGPL from the mono crew. The license is a bit complex:
>    fst/fst/vstwin.c:   GPL (written by torbenh and myself)
>    fst/fst/<others>.c: LGPL (written by mono but drastically hacked
> by us)
> I will correct that in a new release.

Of course I haven't really got a clue, but I'm not sure you need to.  
Since the LGPL is GPL-compatible, I think you can distribute the 
aggregation of the files entirely under the GPL.

> There is no SDK. There is no library, no source files, etc. etc.
> What is required is a pair of header files.

Those two header files are what's distributed as the VST SDK, and 
they're what I meant.

> You do not require any
> VST files to run things based on libfst, only to compile them.
> My reading of the GPL doesn't suggest to me that this is
> incompatible with the GPL. Do you see it otherwise?

Yes.  The headers are source code, the fact that their names end in .h 
is quite irrelevant.  If you build a binary from source code that 
includes those two headers and distribute it under the GPL, you must 
provide (or offer to, blah blah) the source for the headers.  The 
only exception the GPL makes is the infamous "system headers" one for 
code that the user would naturally have as part of their operating 
system already -- which clearly can't be the case for the VST SDK.  
If you can't distribute the source for the headers because of their 
licence, then that licence is incompatible with the GPL.  That looks 
to be the case here, and I think it means that nobody can actually 
distribute libfst.so apart from you personally.

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.

You couid I suppose alternatively argue that the headers just 
constitute a publication of the interface between two modules, in 
which case their contents could probably be rewritten and distributed 
without requiring a licence at all.


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