This is NOT about interfaces!

This is NOT about interfaces!

And this all is relevant... exactly how ?

Well because that clause may or may not be enforceable. If there's copyright "boundary" (there likely is) then it might be harder for the GPL to reach across it. But that'd be something you'd have to argue before a judge and jury.

Let's forget about interfaces, GPL and CDDL for a bit. Let's talk about two writers: Justina and Max. Both created some great stories and now publisher want to publish single book with stories by Justina and Max. Justina granted right to publish stories in any form to everyone but Max does only grant this to anyone who will not publish Justina's creations in the same book as his storis. Can our publisher then publish this book ? Of course not: you need permissions from all authors! Note: stories are totally unrelated - the only connection is single bookcover (and empty piece of paper is hardly copyrightable).

The problem is that that's likely not the some thing. In the case you describe, the publisher almost certainly has contracts with these author. If an author has a clause in their contract that makes their copyright licence conditional on not publishing with the work of some other author, then it is *CONTRACT* law which gives that clause weight, not copyright - contract law is far more flexible.

A licence under copyright alone is more difficult to have mandate restrictions not relating to copyright - you can *grant* rights with a unilateral licence, but you possibly can not take away rights over which you have no claim through copyright, for otherwise copyright licences could make all sorts of silly claims. You can simply disregard such clauses, for they have no effect on copyright (you can't break a copyright licence if copyright is not involved). Least, it used to be that way, until stuff like UCITA came along to start giving shrink-wrap copyright licences more contract-like powers, at least in the USA.

As a thought experiment, imagine if the GPL had a clause stating that you could not distribute GPL works if you also used MS Windows, or if you had a dog. I.e. think of some silly clause which would be legal under contract law (not breaching discrimination laws, etc.) yet has nothing to do with act of copying the work concerned. It's not too hard to think such clauses would be unenforceable, given the right judge ;). In the case of this clause, even more so when the licence *does* allow the act of distributing a GPL work without the OS components it depends on, the contentious components here.

It poses problems both way really. If its not enforceable, that's a problem for any non-copyright related /restrictive/ clauses in licences like the CDDL and GPL. There aren't many such clauses though, but this clause is one. If it's enforceable, then obviously yes there's a theoretical legal and moral problem for Nexenta GNU/OpenSolaris.

However, that's all quite speculative and there's also a decent chance my reasoning is flawed. ;) So lets just assume the clause is quite valid from now on. Where do things stand then? And isn't this a storm in a tea-cup?

Nexenta have a licence to distribute OpenSolaris (the CDDL). They have, other than this complication, a licence to distribute GPL packages. Further, the GPL *does* allow GPL software to depend on non-GPL OS components, even where they are *completely* proprietary, (OpenSolaris is "Free", if not GPL). It also allows GPL software to be distributed in aggregate with non-GPL works, even completely closed proprietary works.

So we're having a big argument because one Free application is being distributed with a Free OS, because the licence of the Free application has an unfortunate oversight in it which neither the licences author nor the author of the application probably ever intended to constrain such distribution.

"May be GPLv3 will solve this problem, may be not - but right now Nexenta is in quite real trouble."

How exactly? They're not in trouble if either:

a) (ideally) The dpkg copyright holder(s) grant a CDDL exception for dpkg. Or even just clearly state "hey, its perfectly ok by us" as an official position - even that would be sufficient legally under the British legal systems in US, UK and elsewhere.

b) (far less good, if only from a moral perspective) The dpkg copyright holder(s) don't sue.

And *no one* but the dpkg copyright holders can sue btw. Their opinion is all that matters. (I not sure what, if any, status those posts on those debian lists have wrt expressing the opinion of the dpkg copyright holders)

If a sensible solution can not found then that means a Free OS and Free applications essentially can not be distributed together, which I think most sides would agree is not a desirable outcome.