Can you alter the MIT license?

[Scott Johnston]

>>  I've considered it doing this with ivtools, and asked for feedback from
>> users.  I got one strong and well reasoned response that opened my eyes to
>> the partially immutable nature of the MIT license.  Since then I have thrown
>> out all the years of assumptions about the BSD license and am trying to
>> rebuild my understanding from the ground up. 
>
>Hmm.  Well, could you summarise the response?

I can try and reconstruct the points we pondered.

I had assumed that the "right to modify" granted by an MIT license included
the right to alter or remove the permission notice from the source code of
derivative works. I reasoned this was the case because it wasn't
specifically ruled out, and because of the commonly accepted practice of
selling X Window binaries with excised permission notice (of course, with
one copy still in the supporting documentation, to give credit where credit
was due, and give fair notice of where a party could find the free source
for themselves).  But is a binary a derivative work?  Or just a use of the
software? 

This other party made a case similar to what has been presented here, that
it would take the agreement of the entire body of copyright holders to
change the permission notice, and that there was nothing in the permission
notice that would allow the relaxing of the original terms in any derivative
work in source form.  This person called the MIT license "congenital", in
that it is something the software is born with that won't go away.

Now I have a new interpretation to ponder which is probably compatible with
the previous paragraph. That the MIT license *can* be changed in derivative
works by adding terms, as long as those terms do not require actions or
grant permissions banned by the original.  But what does this really mean
for MIT style licenses?  Can I add *any* term except 1) a ban on replicating
the permission notice in the documentation, and 2) a requirement that you
must include the names of copyright holders in all advertisements?

I think it interesting that the FSF stopped short of applying the GPL to the
modified X11 sources of libxmi.  Did they do this because they considered
the modifications minor, only upgrades to ANSI standard C?  I thought
aggregrating with GPL code was supposed to override any individual
copyrights.

>
>Some possibly issues:
>
>Is ivtools entirely your copyright?  If not, you can't relicense it
>anyhow. If it's partly your copyright, you could get permission from all
>the other copyright holders to do so (in writing, ideally!).

Here it is:

/*
 * Copyright (c) 1999  Vectaport Inc., I.E.T. Inc, R.B. Kissh and Associates
 * Copyright (c) 1998  Vectaport Inc., R.B. Kissh and Associates, Eric F.
Kahler
 * Copyright (c) 1997  Vectaport Inc., R.B. Kissh and Associates
 * Copyright (c) 1996  Vectaport Inc., R.B. Kissh and Associates, Cider
Press
 * Copyright (c) 1994, 1995  Vectaport Inc., Cartoactive Systems, Cider
Press
 * Copyright (c) 1991 Silicon Graphics, Inc.
 * Copyright (c) 1987, 1988, 1989, 1990, 1991 Stanford University
 *
 * Permission to use, copy, modify, distribute, and sell this software and
its
 * related documentation and data files for any purpose is hereby granted
 * without fee, provided that the above copyright notice appear in all
copies
 * and that both that copyright notice and this permission notice appear in
 * supporting documentation, and that the names of the copyright holders not
 * be used in advertising or publicity pertaining to distribution of the
 * software without specific, written prior permission.  The copyright
holders
 * make no representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 *
 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
 * IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL,
 * INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

Years ago I changed from using specific references (i.e. Stanford and
Silicon Graphics) to a more generic "copyright holders" in the body of the
permission notice.  You can see the permission notice would be quite
unwieldy without this change.  I feel that was entirely within the spirit of
the original license, but I'm no longer sure it is technically permitted. 
Of course I include a copy of the original copyright and permission notice
(of InterViews) in the documentation.

Scott Johnston