CMM support (Was: Re: [Openicc] google SoC starts)

[Craig Ringer]

Graeme Gill wrote:
> Craig Ringer wrote:
>> I would agree with that, though I'm no lawyer. Specifically, a plugin to
>> support the Adobe CMM would not have to be under the GPL because it
>> would not be a derivative work of Scribus. We could produce a non-GPL
>> (say BSDL) abstract CMM API and implement it against lcms and the Adobe
>> CMM. A null/no-op plugin would also not be a bad idea. Scribus's use of
>> this API and linkage to the plugins would in no way imply a derivative
>> work.
> 
> I'm not sure I agree with this analysis. It's not
> necessary that the plugin become a derived work of Scribus,
> but rather that what is distributed (which would
> include the plugin) is a derived work of Scribus.

Indeed.

> If the combined package (work that's distributed) relies
> on the plugin for it's total functionality (i.e. it's optional
> CMM support), then clearly it's more than "mere aggregation",
> and is a derived work of both Scribus and the plugin
> (a collective derived work), and the whole is subject to
> the GPL as a condition of the permission to copy the GPL
> components it's derived from (2a of the GPL).

I'm not sure that's true if the plugin is merely one of many that
provide interfaces to external functionality. Certainly if we bundled
the CMM with Scribus we might have problems, but I'm not sure providing
plug-ins to support for additional user-installed CMMs would be an issue.

In any case, I think we're certainly fine if distribute the plug-ins
separately. The plug-in API we provide in Scribus may permit use under
both the GPL and a less restrictive license, and if it's the *user*
combining Scribus and the CMM via a plug-in we provide separately I can
personally see no possible grounds for objection.

In any case, the Software Freedom Law Centre might be able to offer
advice if anybody's really worried. Personally, I wouldn't be...
especially since the only people legally empowered to do more than whine
about GPL infringement (if there were any, which I do not believe there
will be) are copyright holders. The vast majority of Scribus was written
by a small number of people who are still active in the project, and I
simply don't see anyone kicking up a fuss.

Personally I prefer the MPL and the LGPL to the full GPL for most
things... not least because of issues like this.

> So if Scribus is GPL, then the plugin "shim" has to
> be GPL,

Not quite. We can publish a plugin API intended for public
implementation under a less restrictive license. The code implementing
it in Scribus is GPL, but it's just implementing the published
interface, and plugins would be built against the completely independent
 non-GPL plugin headers.

So long as we're not bundling the plug-ins with Scribus, that's a no
brainer.

> and any non-GPL CMM's can't be distributed with
> the Scribus package (even if their copyright owners
> permitted this) because they add functionality (even if it
> is optional), and would be part of the collective derived work.

I'm generally inclined to agree with this part of the assessment.