CDDL+GPL and stuff

[Arnoud Engelfriet]

Konstantin Svist wrote:
> What kind of problems would those be? The incompatibility seems to be on 
> GPL-side only; CDDL explicitly permits linking to other licenses - so 
> it's not like Sun will retaliate against the poor bastard who put the 
> two together.

The GPL requires that any derivative works you distribute are
available under the GPL terms. If any components are under a
different license, the terms of that license must be at most
a subset of the terms of the GPL. That's called "compatible".

For example the MIT license is compatible, as its terms are
basically "do not remove notice and do not sue if it breaks".
That is also in the GPL.

The CDDL however is not GPL compatible:
"It requires that all attribution notices be maintained, while the GPL only
requires certain types of notices. Also, it terminates in retaliation for
certain aggressive uses of patents. So, a module covered by the GPL and a
module covered by the CDDL cannot legally be linked together."
http://www.gnu.org/philosophy/license-list.html#CDDL

> What about GPL Exceptions? I've read about OpenSSL exception 
> (http://en.wikipedia.org/wiki/OpenSSL_exception#GPL_exception). Who has 
> the power grant/append such an exception?

The copyright holders to the GPL work. 

> What if there's a separate from kernel project, which will keep all the 
> necessary changes to the Linux kernel to enable users to compile the 
> merged code and use it for themselves? Would this be possible under some 
> license?

The legal issue here is whether a kernel module, by itself,
qualifies as a derivative work of the Linux kernel. This is an
open question.

When code is written specifically to function as a Linux kernel
module, probably that code qualifies as a derivative work. 

In the particular case of a pre-existing work that is merely
adapted to work with the Linux kernel, arguably the adapted
code does not qualify as a derivative work. 

Arnoud

-- 
Arnoud Engelfriet, Dutch & European patent attorney - Speaking only for myself
Patents, copyright and IPR explained for techies: http://www.iusmentis.com/
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