Subject: Re: termless copyright and patents
From: <stephen@xemacs.org>
Date: Wed, 4 Oct 2006 00:31:06 +0900

Ben Tilly writes:

 > Consider the following argument.  Section 6 says Alice cannot impose
 > further restrictions on the recipients' exercise of the rights granted
 > herein.  One of the rights granted herein is the right to make
 > modifications as long as section 2 is satisfied.  But if Alice sues
 > she is saying, "You may make any modifications you wish as long as you
 > don't wind up violating one of my other patents."  Therefore she is
 > restricting the freedom guaranteed in section 2.
 > 
 > It would be interesting to see this argument go to court.  I have no
 > idea whether it would hold up, or what the consequences would be if it
 > did.

I'd not be surprised if it got summarily dismissed.  Here's why.

What is a copyright license?  Permission to copy *existing text*.  It
does not apply in any way to original text, it can neither restrict
nor grant permission for "creation" of original text.  The right
granted by the right to modify is the right to *use this text* in
combination with new text, possibly after deleting from this text.
*No rights are granted concerning the new text*, because they don't
need to be: a license can't restrict your behavior regarding new text
in any way in the first place.

Thus, any covenant in the license will only apply to *text obtained
by copying from the work*.  Since an implementation of a claim not
embodied in the work a fortiori cannot be copied from the work,
regulating such implementation is outside of the scope of a copyright
license, including the covenants.

Of course you could write a separate covenant that *explicitly* grants
broader rights, eg,

    The conveyor of this Software covenants that he will ensure that
    none of his patents, currently owned, or granted or acquired in
    the future, will ever be enforced by him or anybody else under any
    circumstances.

But I think the natural interpretation under copyright law is that
unless very explicitly stated otherwise, this kind of covenant is to
refrain from use of patents to interfere with the rights granted by
the copyright license.  Ie, to copy (and perhaps modify) specific text
which implements a patent claim, and thus the covenant only applies to
that claim.

Of course in the case of a license which is a contract, anything goes
(but get it in writing! :)

IANAL, this is not legal advice, and I don't even recall reading it in
Larry Rosen's book (although it might be there).  Nevertheless, I
think I finally "got it". :-)