[License-discuss] Open Source Eventually License Development

[zooko]

On Sun, Aug 18, 2013 at 06:29:26PM -0400, Bradley M. Kuhn wrote:
> Richard Fontana wrote at 08:20 (EDT):
> > Not with an exception in the GPLv2 exception sense, and not without the result being (A)GPLv3-incompatible, since under TGPPL each downstream distributor appears to be required to give the grace period.
> 
> ISTR that Zooko was willing to drop that requirement for the sake of simplicity.  But maybe I'm misremembering.  Zooko?

Short version:

I'm willing to allow a line of works licensed under TGPPL to eventually give
rise to derived works licensed under GPL. However there is a specific thing
that I'm unwilling to allow: that if I make a work available to you under
TGPPL, that you take advantage of the 12 month grace period for keeping your
derived work proprietary, and then deny the grace period option to derivors
immediately downstream from you.

I think both of the above are already achieved by Tahoe-LAFS's currently
dual-licence (in which you may use Tahoe-LAFS under GPL or TGPPL at your
option).

I currently think it is possible to achieve both of the above in a future
version of TGPPL, by saying: this is my work, it is licensed to you under
TGPPL, the TGPPL stipulates that you can use my work only if you either (a)
license your derived work under GPL *immediately* (just as standard GPL
requires), or (b) license your derived work under TGPPL within 12 months.


Long version:

Suppose that person A produces work "a1" and licenses it to person B under this
licence, and person B produces a work "b1" derived from a1, and then person C
wishes to produce a work derived from b1.

I want all of the following:

i. B has the option to keep b1 proprietary for a limited time (12 months).

ii. B has the option to *instead of making b1 proprietary for a limited time*
to make b1 be unmodified-(A)GPLv3-licensed.

iii. B does not have the option to make b1 proprietary-for-a-limited-time and
then subsequently license b1 as unmodified-(A)GPLv3-licensed, thus denying to
person C the option to make c1 be proprietary-for-a-limited-time.

I think I already have this with the Tahoe-LAFS codebase, because of the way
that it is dual-licensed under TGPPL v1+ or GPLv2+ at your option. It satifsies
(i), because B can use a1 under the TGPPL. It satisfies (ii), because B can use
a1 under the GPL. It satisfies (iii), because the TGPPL does not allow B to
keep b1 proprietary-for-a-limited-time and then license b1 under GPL to C.

The only (?) downside to this scheme is the possibility of a licence-fork:
someone could take a1 (e.g. the current version of Tahoe-LAFS) under either GPL
or TGPPL and release a dervied work (b1) under GPL-only, or under TGPPL-only,
and then downstream users from them would not have the dual-licence option.

In light of the licence-fork problem, I add below desiderata (iv) and (v). I
don't believe it is possible to achieve desideratum (v) so I'm willing to
forego it.

iv. (No licence-fork away from GPL) B does not have the option to distribute,
or to host for the use of others, b1 without C eventually (within 12 months)
gaining the unmodified-(A)GPL-licence to use b1.

[not achievable] v. (No licence-fork away from TGPPL) B does not have the
option to distribute, or to host for the use of others, b1 without C eventually
(within 12 months) gaining TGPPL-rights to use b1.

Regards,

Zooko