Jumping the licensing shark

Posted Mar 30, 2023 15:29 UTC (Thu) by Wol (subscriber, #4433)
In reply to: Jumping the licensing shark by ksandstr
Parent article: Jumping the licensing shark

> Whether this allows a program previously copylefted due to derivation from Readline to become non-copylefted if it were retargeted to a non-copylefted implementation of the same interface is between the reader and his time machine.

Readline's licence does not affect the licence used on said program. Obviously, if I've released a proprietary program, using Readline, I have to allow my recipients to distribute my code under the GPL. I also can't revoke the GPL on the copies they've already got.

But there's nothing stopping me replacing Readline with the BSD equivalent, and then no longer distributing source. Whether that's wise/economically feasible is another matter.

Cheers,
Wol

Jumping the licensing shark

Posted Mar 30, 2023 15:46 UTC (Thu) by ksandstr (guest, #60862) [Link] (1 responses)

On the contrary, GNU Readline is the canonical example of a library first developed and licensed under the strongest copyleft. Therefore a program derived from it, such as all Readline clients written before non-copyleft substitutes were available, is a derivative of GNU Readline in particular. Arguably that program will remain derived even if all reference to specifically GNU Readline (and not a substitute) were subsequently removed. For alternate interpretations, consult your time machine and/or memory hole.

Jumping the licensing shark

Posted Mar 30, 2023 17:07 UTC (Thu) by Wol (subscriber, #4433) [Link]

Congratulations! You have just succeeded in copyrighting an API, and causing serious trouble to the entire computing industry ...

The licence of Readline is not allowed to affect the licence on the SOURCE of my program. If I wish to include Readline in my program, I have to allow my source to be distributed under the GPL, too.

But, as I said, as soon as I swap Readline for the BSD equivalent, I no longer have to distribute my source under the GPL. I can't do anything about the copies already out there, but if things go right for me, they will wither on the vine. If things go wrong, ... well I'm probably no worse off than I was to start with.

Cheers,
Wol