Do we still need weak copyleft? (was Re: Exceptions to copyleft-next)

[Stefano Zacchiroli]

On Mon, Jul 13, 2026 at 10:25:39PM -0400, Richard Fontana wrote:
> Me too. I've thought for some time that weak copyleft is a failed (or
> now-irrelevant) paradigm, if only because of the political success of
> noncopyleft FOSS licenses.

I think so too. But is that a good enough reason to give up on weak
copyleft as a licensing scheme that could make sense in general, simply
because it has failed to gain traction so far? (Yes, I realize that "so
far" spans multiple decades, but still.)

The software commons would, in my view, be better if, for example,
OpenCV had been released under a weak copyleft license rather than the
Apache License it uses today. Even if OpenCV's success plausibly stems
from not being released under weak copyleft, what if a different future
library *could* succeed and become important under a weak copyleft
regime? Is there any policy or strategic reason to preclude that
possibility?

> GPL exceptions actually worked pretty well for many base-GPLv2 (and
> perhaps base-GPLv3) projects; perhaps the tradition of having
> relatively simple exceptions could be adopted by the future
> copyleft-next community.

You surprised me with that last paragraph; it seems to go in a different
direction than the rest of the mail. Are you saying that an exception
that implements weak copyleft on top of the standard copyleft-next is
something you would be willing to consider? If so, that would be
analogous to how LGPL-3 is implemented today, and I'm not sure what
we're discussing in this subthread anymore :-).

Cheers
-- 
Stefano Zacchiroli - https://upsilon.cc/zack
Full professor of Computer Science, Polytechnic Institute of Paris
Co-founder & Chief scientific officer Software Heritage