[License-review] For Approval: License Zero Reciprocal Public License

[Kyle Mitchell]

Nigel,

Thanks for your response.

If you'll forgive me generalizing a bit, I
think you broached two main topics:

1. Triggering source publication requirements
   on use, rather than distribution of
   modifications.

I hope you'll forgive me starting out by
saying that while this is absolutely the part
of L0-R most worth discussing, I don't
believe this choice of trigger affects
whether L0-R meets the Definition.  I don't
read any part of OSD to compel any particular
kind of trigger for copyleft requirements.

I usually refer to troubles complying with
license conditions for software that you've
received from someone else "downstream
compliance issues".  Alas, downstream issues
aren't peculiar to L0-R, or even to copyleft
licenses generally.

Take a typical attribution requirement under
a permissive license, like the two-clause BSD
License.  If A writes software and licenses
BSD-2-Clause, B makes modifications and gives
C a copy without A's copyright notice, then C
might fail to meet the attribution condition
of A's license if C makes a copy for D
without A's notice, and end up without a
license C needs.

The same can happen with GPL-style copyleft
conditions.  If A writes software and
licenses GPL-2.0, B makes modifications and
gives C a binary copy with access only to B's
new source, then C's at risk of failing to
meet the source condition of A's license if C
distributes with further modifications, and
only B and C source.  More generally, one
purpose of GPL-style copyleft, as an
implementation of Software Freedom, is to
ensure that any licensee can also be a
developer.  The distinction between user and
developer dissolves.

The only solution to eliminating downstream
compliance issues I'm aware of is permissive
licensing utterly without condition, such as
under The Free Public License / 0BSD or The
Unlicense.  Under a direct-licensing model,
where everyone receives permission directly
from the copyright holders, through the
public license, any condition gives a license
teeth that can bite anyone downstream.  L0-R
has license conditions, and therefore
potential downstream issues.  But it tries to
mitigate headache in a couple of ways.

First, condition 3 requires that source code
_be_ published, but not that any or every
specific licensee _do_ the publishing.  If A
licenses code L0-R, B makes modifications,
licenses those modifications under an Open
Source license, and publishes code, users of
B's modified version don't trip over
condition 3 by executing or developing with
A's software.

Second, L0-R preserves BSD-2-Clause's
redistribution conditions.  It modifies them
only to require preservation of notice of a
source code repository, in addition to the
copyright notice.  This is meant to help
ensure that not only license-terms
information, but also source availability
information, travels with the software
wherever it roams.

2. Issues related to license changes.

You pointed out at least two ways in which
the licensing situation under L0-R can drift
away from the situation when the license text
is originally applied to the code.  Both
involve situations where licensees might have
to look beyond the particular form of the
software they've obtained to assess rights.

First, there's the automatic waiver.  The
concern that provision tries to address is a
kind of "orphan code" tragedy, where the
creators would be willing to make a deal for
other license terms, or relicense, to permit
non-Open Source use further down the line,
but can't be found or bothered. Dual
licensing stops, and all that's left is a
very exacting public license.

The most rigorous way to address that concern
is simply to tell licensors that they ought
to relicense their software under permissive
terms when and if the time comes.  Or to set
up some facility to offer alternative
licenses indefinitely.  I have little hope
for either of those approaches lasting the
test of time.

That being the case, we need some kind of
trigger for, effectively, automatic
permissive relicensing.  Automatic in the
sense of requiring no further action by the
licensor.  One approach would be to set a
date in the license, but licensors would only
very rarely guess the right date ahead of
time.  Assessing whether a licensor has
_failed_ to take some action, like offer
alternative licenses, gives licensors more
control, over time, of waiver. But from the
licensee point of view, it involves proof of
a negative.  The language puts the burden of
that uncertainty where it belongs, on those
who should seek an alternative license if
they can get one.

As for retroactive changes to the agent, and
other changes to license information for a
project, over time and over versions, I'm
afraid those issues aren't peculiar to L0-R,
either.  Fundamentally, the model of terms in
public licenses distributed the same way as
the software creates issues for those who
want to make changes in what's already been
distributed far and wide.

If you license version 1.0 of a project under
GPL-2.0, and later decide to move to
GPL-3.0+, you're faced with the problem of
informing folks with copies of 1.0 that only
mention GPL-2.0.  If you're using a third
party distribution service, you probably try
to alter the artifacts they distribute.  And
you likely publish a notice on your website
and in README or similar of later versions of
your project, mentioning that prior versions
have been relicensed.  You'd do much the same
for an L0-R agent change.

The information dissemination problems here
are mitigated somewhat by the copyright and
repository notices.  If you're curious
whether the licensing agent for a project has
changed, you may find the information you
need at the repository.

3.  Concerns about the licensing agency.

I'll put some thought on dropping the current
language about an agent in favor of a
requirement to preserve any separate notice
about where alternative licenses are
available.  Perhaps:

    ...

    Alternative Licenses Available:
    <Information>

    ...

    1. ... must retain all the notices
       above...

    2. ... must reproduce all the notices
       above...

    3. ... This condition is waived if
       alternative licenses permitting those
       uses cease to be available for <Waiver
       Period> consecutive calendar days.

The constraint foremost in in mind is
ensuring that downstream recipients have some
way to identify where alternative licenses
can be got if needed, and some evidence to
authenticate those purporting to offer
alternative licenses as those actually
capable of doing so.

In general, it falls on licensors to maintain
a dual-licensing practice to avoid the
automatic waiver.  There is always an issue
of trust, and verification, when delegating
important duties to others.  Also opportunity
and specialization.  The core idea behind
licensezero.com is a "dual-license vending
machine" that stands ready to vend
alternative licenses, 24/7.  To give
small-scale companies and independent
developers the machinery they need to run
dual-licensing businesses.


As long as there be law, there will be
pondering.  And lawyers, I'm afraid.  My goal
with L0-R could not be perfect clarity, but a
relative clarity, constrained in brevity.  A
natural tension, there.

Thanks once more for time and thoughts.

Best,

K

-- 
Kyle Mitchell, attorney // Oakland // (510) 712 - 0933