Re: [PATCH v2] module.h: add copyleft-next >= 0.3.1 as GPL compatible

[Rusty Russell]

Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> writes:
> On Thu, Jun 30, 2016 at 03:53:27PM -0700, Luis R. Rodriguez wrote:
>> copyleft-next [0] [1] is an openly evolved copyleft license, its an
>> effort to evolve copyleft without participation of the Church (TM)
>> or State (R), completley openly to the extend development and
>> discussion of copyleft-next by participants of the copyleft-next
>> project are governed by the Harvey Birdman Rule [2].
>> 
>> Even though it has been a goal of the project to be GPL-v2 compatible
>> to be certain I've asked for a clarification about what makes
>> copyleft-next GPLv2 compatible and also asked for a summary of
>> benefits. This prompted some small minor changes to make compatiblity
>> even further clear and as of copyleft 0.3.1 compatibility should
>> be crystal clear [3].
>> 
>> The summary of why copyleft-next 0.3.1 is compatible with GPLv2
>> is explained as follows:
>> 
>>   Like GPLv2, copyleft-next requires distribution of derivative works
>>   ("Derived Works" in copyleft-next 0.3.x) to be under the same license.
>>   Ordinarily this would make the two licenses incompatible. However,
>>   copyleft-next 0.3.1 says: "If the Derived Work includes material
>>   licensed under the GPL, You may instead license the Derived Work under
>>   the GPL." "GPL" is defined to include GPLv2.
>> 
>> In practice this means copyleft-next code in Linux may be licensed
>> under the GPL2, however there are additional obvious gains for
>> bringing contributins from Linux outbound where copyleft-next is
>> preferred. To help review further I've also independently reviewed
>> compatiblity with attorneys at SUSE and they agree with the
>> compatibility.
>> 
>> A summary of benefits of copyleft-next >= 0.3.1 over GPLv2 is listed
>> below, it shows *why* some folks like myself will prefer it over
>> GPLv2 for future work.
>> 
>> o It is much shorter and simpler
>> o It has an explicit patent license grant, unlike GPLv2
>> o Its notice preservation conditions are clearer
>> o More free software/open source licenses are compatible
>>   with it (via section 4)
>> o The source code requirement triggered by binary distribution
>>   is much simpler in a procedural sense
>> o Recipients potentially have a contract claim against distributors
>>   who are noncompliant with the source code requirement
>> o There is a built-in inbound=outbound policy for upstream
>>   contributions (cf. Apache License 2.0 section 5)
>> o There are disincentives to engage in the controversial practice
>>   of copyleft/ proprietary dual-licensing
>> o In 15 years copyleft expires, which can be advantageous
>>   for legacy code
>> o There are explicit disincentives to bringing patent infringement
>>   claims accusing the licensed work of infringement (see 10b)
>> o There is a cure period for licensees who are not compliant
>>   with the license (there is no cure opportunity in GPLv2)
>> o copyleft-next has a 'built-in or-later' provision
>> 
>> [0] https://github.com/copyleft-next/copyleft-next
>> [1] https://lists.fedorahosted.org/mailman/listinfo/copyleft-next/
>> [2] https://github.com/richardfontana/hbr/blob/master/HBR.md
>> [3] https://lists.fedorahosted.org/archives/list/copyleft-next@xxxxxxxxxxxxxxxxxxxxxx/thread/JTGV56DDADWGKU7ZKTZA4DLXTGTLNJ57/#SQMDIKBRAVDOCT4UVNOOCRGBN2UJIKHZ
>> 
>> v2:
>> 
>> o extend checkpatch.pl with copyleft-next as well for
>>   MODULE_LICENSE() check - as suggested by Paul Bolle.
>> 
>> Cc: copyleft-next@xxxxxxxxxxxxxxxxxxxxxx
>> Cc: Richard Fontana <fontana@xxxxxxxxxxxxxxx>
>> Signed-off-by: Ciaran Farrell <Ciaran.Farrell@xxxxxxxx>
>> Signed-off-by: Christopher De Nicolo <Christopher.DeNicolo@xxxxxxxx>
>> Signed-off-by: Luis R. Rodriguez <mcgrof@xxxxxxxxxx>
>
> Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

Adding a license here implies we accept that it's actually GPLv2
compatible.  And IANAL.

If such-licensed code gets openly accepted into the kernel, and nobody
complains, I'll send this to Linus.  Not a moment before.

Thanks,
Rusty.