On Tue, 13 May 1997, Curt Sampson wrote:

> On Tue, 13 May 1997, Bill Studenmund wrote:
> 
> > This restriction is why Linux and *BSD can't share code too well. There's
> > a lot of stuff in our kernel which isn't GPL'd but can be distributed as
> > long as you adhere to its conditions. Well, since its conditions aren't
> > GPL (nor have the restrictions of GPL), to GPL it would violate these code
> > chunks' copyright.
> 
> Please do not confuse copyright and licencing conditions. Copyright
> has little to do with this discussion.
> 
> Last time I looked at this the GPL did not have any clauses that
> were incompatable with the standard Berkeley licence, nor did the
> Berkeley licence have any clauses that were incompatable with the
> GPL. So it is perfectly possible to distribute something under an
> amalgam of both. I don't know what you believe the incompatability
> is here.
> 
> I believe the reason that NetBSD has no GPL code in the kernel is
> that it couldn't be distributed without putting the entire kernel
> under GPL, which many of us find overly restrictive.

I think I meant license all the way.

The incompatability is that if you distribute a binary with GPL'd code in
it, all the source has to be GPL'd and distributed. The "under terms of
this license" phrase in the part which has been snipped is the killer.

As I understand it (as it was explained to me when this Q came up on
tech-kern), parts of our kernel (and the other *BSD kernels) come with a
license which says you can't change the license. But that license isn't
GPL, so you (we, whomever) can't mix the two and satisfy both licenses at
once. The Linux folks ran into this problem with the MkLinux microkernel,
as it's under a BSD-ish license.

The combo licenses I've seen say you can either distribute this code under
the terms of the GPL, or under this here license (which looks very
BSD-ish). /dev/random from FreeBSD does this.

Take care,

Bill