Subject: RE: Compatibility of the AFL with the GPL
From: "Lawrence E. Rosen" <>
Date: Wed, 12 Mar 2003 12:36:39 -0800

Answers interspersed.  /Larry

> -----Original Message-----
> From: John Cowan [] 
> Sent: Wednesday, March 12, 2003 11:20 AM
> To:
> Cc: 'Bjorn Reese';;
> Subject: Re: Compatibility of the AFL with the GPL
> Lawrence E. Rosen scripsit:
> > And anyone who has a copy of W+X or W' has two licenses, one from 
> > Person A (for that part that was W) and one from Person B 
> (for W+X or 
> > W'). Person A is not responsible in any respect for W+X or W'.
> The key question:  If Person C who has W' sues Person A for 
> patent infringement, does that void his license to do things with W'?

If C sues A for patent infringement, C can no longer copy, modify or
distribute W, or W+X, or W', because his license to do those things with
W is terminated.

If C sues B for patent infringement, A doesn't care.  Unless, of course,
B licenses using the Mutual Defense provision, in which case A and B
defend each other by terminating both licenses!

> If so, and if X is under the GPL, then W' cannot lawfully be 
> created, because it is a derivative of two works with 
> contradictory licensing terms.

What's contradictory?  I agree there is an encumbrance based on the
license for W, but it is a contingent encumbrance that becomes effective
only when C elects to sue A for patent infringement.  Nothing in the GPL
prohibits such a contingent termination provision for a component of a
GPL-licensed derivative work.  In any case, the licensee can read about
those contingencies via the license notices in the source code.  (In
case you were wondering, section 7 of the GPL doesn't apply to this

> If not, I suggest a sentence be added to the AFL saying that 
> the M.T.P.A. clause is expressly inapplicable to derivative 
> works unless the work as a whole is licensed under a license 
> containing the M.T.P.A.  (More gracefully worded, preferably.)

I don't think the added wording is necessary because the AFL *is*
compatible with the GPL.


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