Viral permissiveness

Ben Tilly btilly at
Tue Jan 20 19:13:07 UTC 2009

On Tue, Jan 20, 2009 at 7:00 AM, Steve Thomas
<steve.thomas.private at> wrote:
> Does a license already exist that, for any such chain as in (2), would
> preclude step (4) whilst allowing (5) and (6) in the event that Mr
> Takesallsorts chooses to distribute his derivative work ? Is it
> possible for any such license to be GPL-compatible ?

Almost certainly this is impossible.

Furthermore there is an interesting irony here.  Suppose you came up
with a license that is permissive like the BSD but has a restriction
preventing its appropriation by GPL advocates.  Suppose you have a
project under this license and wish to borrow some BSD code, which you
then make changes in.   Guess what?  If you license your changes under
your license, then the original BSD project can't accept them back
without being forced to change their license!  No matter how great
your intentions, from the point of view of a BSD project, your
anti-GPL license is as bad as the GPL license itself!

It is in the nature of being permissive that you can't accept
restrictions on code.  Any kind of restrictions.


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