[License-discuss] Open Source Eventually License Development

[zooko]

Folks:

I'm not sure, but I think some people on this thread might be confusing two
different issues.

Suppose Person A makes a work a1 and licenses it to Person B under licence L,
and then Person B makes a derived work b1 and licenses it to Person C, also
under licence L, and then Person C makes a derived work c1.

Some of the discussion on this thread seems to be about what obligations Person
A has to Person B. That's the first of the two issues.

The oft-cited example of the Aladdin Software releasing older versions of
Ghostscript under GPL is about the relationship between Person A and Person B.

That's not what I'm concerned about. What I think is important, and the reason
I wrote and used the Transitive Grace Period Public Licence, is about the
relationship between Person B and Person C.

If Person A released a1 under the GPL (either immediately or after a delay --
it makes no difference to this), then this gives Person B certain options for
how they can use work a1, and how they can license work b1. Namely, it grants
them permission to make their derived work provided that they license it to
Person C (and everyone) under GPL, and therefore that they grant Person C full
permissions to b1 immediately upon redistributing b1. We could say that Person
B is granted permission to keep b1 proprietary for a duration of 0 months.

If Person A released a1 under a permissive licence, then this grants to Person
B the option to keep b1 proprietary for as long as they like. We could say that
Person B is granted permission to keep b1 proprietary for a duration of
infinity months.

If Person A released a1 under the TGPPL, then this gives Person B options
different to either of the other two scenarios above. Now Person B is granted
permission to keep b1 proprietary for a duration of 12 months.

So the effect of the Person A's use of TGPPL on Person B is completely
different from the old Aladdin Software policy.

Regards,

Zooko