[License-review] Sublicensing

[John Cowan]

Jim Wright scripsit:

> Well, it seems to me to be what allows the mechanics of copyleft license
> compatibility to work at a fundamental level - if I cannot sublicense
> a copy of an MIT licensed header file to a subsequent recipient under
> the GPLv2, I don't know how I can include that header file in a GPLv2
> licensed c file and then distribute the compiled object file and
> corresponding source, because the recipient of the combined module
> needs to get "each and every part" under the GPLv2.

I'm pretty sure that's a misreading of the GPLv2.  The relevant sentence
is:  "But when you distribute the same sections as part of a whole which
is a work based on the Program, the distribution of the whole must be on
the terms of this License, whose permissions for other licensees extend
to the entire whole, and thus to each and every part regardless of who
wrote it."

Note that it does not say "whose permissions and restrictions".  So this
means that if part of the code is released under a license that grants
at least the same permissions as the GPL, and does not impose further
restrictions, the GPL is satisfied.

The implementation of the Pure programming language is packaged as
a library issued under a permissive license which comes with two main
programs.  Main-1 invokes routines from a GPLed third-party library, and
therefore is itself under the GPL, as is any binary version built from it.
Main-2 does not invoke such routines and so has less function than Main-1,
but it is under the permissive license, so it can be reused in non-GPLed
programs.  The author originally wrote only Main-1, and I and others
persuaded him to make the changes to produce Main-2 and package both.
We couldn't do it because of the GPL, but the author is of course not
bound by his own license.

-- 
John Cowan          http://www.ccil.org/~cowan        cowan at ccil.org
My confusion is rapidly waxing
For XML Schema's too taxing:
I'd use DTDs / If they had local trees --
I think I best switch to RELAX NG.