license-mix, legal consequences?

[Henningsen]

I will only integrate contributor's code into my codebase if they hand over
copyright to alifegames.com (in exchange for a fair share of any profits
that may derive from commercial licenses to the code in the future), so I
will be able to release my own core code at any time under any license I
wish. What I am wondering about is the code that comes into the project with
other copyrightholders, and under a license different from the GPL, e.g. the
MIT license. The GPL states:

2.b) You must cause any work that you distribute or publish, that in whole
or in part contains or is derived from the Program or any part thereof, to
be licensed as a whole at no charge to all third parties under the terms of
this License. 

My understanding is this: As the copyrightholder to my code, even if I
release it under the GPL, I am not bound by the terms of the GPL, and can
include code under a different license such as the MIT license. However, if
someone else uses my code under the terms of the GPL, and wants to release a
modified version of my code, then according to 2.b) he would have to license
the entire program under the terms of the GPL, *including the parts that he
received under the terms of the MIT license*. I had been thinking that it
would not be legal to simply take MIT licensed code (or Tcl/Tk licensed
code) and without permission of the copyright holder re-release it under the
GPL.

The responses I got on the list seem to indicate that I am wrong, and this
re-release under a different license that imposes more conditions would in
fact be legal. However, no one addressed this point directly and clearly,
and I am still unsure of the legality of that process. Would anyone be
willing to address this directly?

Peter Henningsen
alifegames.com

At 12:45 PM 6/19/01 -0700, Danese Cooper wrote:
>>At Sun, we license OpenOffice.org code under both the LGPL and SISSL.
>>Since only the copyright holder can change licensing terms for a body 
>>of code, we collect copyright assignments from contributors (whether 
>>they are working under LGPL or SISSL).  The point is that we have to 
>>work at keeping the codebase "whole" under both licenses.
>>
>>About including code you don't "own" (by copyright) in such a scheme.  In 
>>NetBeans there were several libraries which we didn't own and didn't have 
>>rights to redistribute.  We included these as binaries with the author's 
>>permission and modified our build system to use the binaries...
>>
>>Danese
>>
>>>on Sun, Jun 17, 2001 at 08:38:55AM -0300, Henningsen (alg at glinx.com) wrote:
>>>> I want to release code I write myself under a dual license scheme,
>>>> both GPL and commercial license, the latter for people who want to use
>>>> the code in closed source projects. In my project I would like to
>>>> include code released under the Tcl/Tk license model ("keep copyright
>>>> notices in place, and keep this license text with the code"), and code
>>>> released under the MIT license. 
>>>> 
>>>> I checked on the FSF's site whether these licenses are compatible with
>>>> the GPL, and didn't find anything. Are they or are they not? And if
>>>> they're not, would that mean that people who want to use my
>>>> GPL-released code could not also use the code modules with
>>>> incompatible licenses unless they got a special permission from me (in
>>>> effect a free commercial license)?
>>>
>>>Peter:
>>>
>>>First, IANAL.
>>>
>>>Dual licensing of your own code doesn't (generally) require
>>>"compatibility" between licenses, defined as the ability for software
>>>under one license to be used under the terms of another.  
>>>
>>>This is effectively a logical OR:  compatibility requires that,
>>>excepting other arrangements with the copyright holder(s), you can use
>>>alternative or additional licensing terms.  This is a small set of
>>>licenses.
>>>
>>>Dual (or multiple) licensing, on the other hand, is a logical AND.
>>>You're saying that any of the specified licenses is sufficient to meet
>>>the legal obligations for software copying, modification, distribution,
>>>or other 17 USC (or Berne, internationally) exclusive rights under
>>>copyright.  
>>>
>>>The issue that may then arise is the introduction of third-party code
>>>into your project.  So long as this code is introduced under the same
>>>dual/multi license terms, there are no compatibility issues raised.
>>>However, if code is contributed under only one, or some other subset, of
>>>licenses, the codebase as a whole becomes restricted as to which
>>>portions can be used under what terms under altnernative licensing
>>>arrangements.
>>>
>>>As an example, I do work under Python.  Until now, Python has been
>>>licensed under terms similar to the BSD/MIT license.  Last week, Guido
>>>van Rossum announced that license compatibility with the GNU GPL had
>>>been achieved.  I would prefer to license my own code under the
>>>GPL/LGPL, and preferably no other terms.  This could create a conflict
>>>for those who are using Python in, say, proprietary applications, but
>>>would then have to determine whether or not they could incorporate code
>>>authored by me, and/or under what terms.
>>>
>>>Multiple licensing is an interesting hack, but it's not without its own
>>>set of additional issues as well.
>>>
>>>In your own case, my general understanding is that the MIT and Tcl/Tk
>>>licenses should be compatible. 
>>>
>>>I'd be interested in other viewpoints on this.
>>>
>>>-- 
>>>Karsten M. Self <kmself at ix.netcom.com>    http://kmself.home.netcom.com/
>>> What part of "Gestalt" don't you understand?       There is no K5 cabal
>>>  http://gestalt-system.sourceforge.net/         http://www.kuro5hin.org
>>>   Are these opinions my employer's?  Hah!  I don't believe them myself!
>>
>>
>>
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