[License-discuss] Ethical open source licensing - Persona non Grata Preamble

Richard Fontana rfontana at redhat.com
Mon Feb 24 13:44:04 UTC 2020

On Mon, Feb 24, 2020 at 4:06 AM Stefano Zacchiroli <zack at opensource.org> wrote:
> On Fri, Feb 21, 2020 at 11:26:25AM -0800, Brian Behlendorf wrote:
> > One more practical and probably negative impact: it will always be
> > easier to add new names than to remove old ones, because adding new
> > names is a simple sublicense that can be done by anyone, but removing
> > a name will require a relicense with the consent of every contributor
> > who contributed under that license.
> I think this can be fixed by having some sort of proxy clause, similar
> to what the *GPL3 family of licenses support to decide on the "or later"
> license version trigger. You just delegate the ability to update the PNG
> preamble to some body, such as the non-profit steward of the project,
> and be done with it.

In practice, though, this is unlikely to make much of an impact on
reversing or reducing the propagation of old names in the PNG
preamble, because most downstream licensees can't be expected to
update their copy of the preamble. The release of new versions of
widely-used de facto standard FLOSS licenses by license stewards is
not entirely analogous but FWIW the one major experiment we have,
GPLv2 to GPLv3, suggests that the new release isn't likely to have
much effect on either non-maintained or actively-maintained existing
uses of the older release. True, the direct targets of the older PNG
could update their own copies of the preamble without much trouble, if
the proxy authorizes this (or if the PNG including a specific set of
names is maintained by a license steward and the steward releases a
new license version) but they can't do anything about upstream or
"side-stream" copies, which might be numerous. Which may be tolerable,
or not, but it depends on the nature of the content of the PNG, in my


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