Open Source License Question

Kenneth Dombrowski kdombrowski at
Fri Oct 29 06:03:11 CEST 2004

Hi, I was just browsing the group as a newbie to python, and I would 
hate to be thought (or be baited by) a FOSS licensing troll with my 
first post, so I apologize if these issues have been gone over already; 
in fact several people have said that they have, but I am compelled to 
reply to this thread:

Peter Hansen wrote:
> Dan Perl wrote:
>> Michael, I have one comment in-line (see below), but other than that I 
>> can only say that I chose GPL for my own project.  It may discourage 
>> use of my code for commercial purposes


I can only assume you're referring to the restriction that authors of 
non-free software can't link to your libraries

With your code under the GPL, anybody can use your code for commercial 
purposes, or any other purposes.  Anybody can sell it, anybody can link 
to it and sell the derivative work, with the provision that in that case 
they use the GPL for that derivitave work

> This seems like an appropriate post to which to attach a reference
> to a nice article contrasting the GPL and the Mozilla Public License
> (MPL):
> Summary of that essay, in the words of its author:

This is a very misleading article to point someone to.

in the words of its author:

"The GPL prevents code from being sold by itself or as part of a larger 

This is thoroughly false.  There is no restriction on selling GPLed 
software; from the FSF GNU GPL FAQ:

"Does the GPL allow me to sell copies of the program for money?
     Yes, the GPL allows everyone to do this. The right to sell copies 
is part of the definition of free software. Except in one special 
situation, there is no limit on what price you can charge. (The one 
exception is the required written offer to provide source code that must 
accompany binary-only release.)"

He continues,

"However, it leaves the door open for the authors to commercially sell 
the code under different licensing terms if they so choose.
For example, this can easily occur:

    1. a single author may initially release code as GPL;
    2. the author later decides that the code has commercial viability;
    3. the author stops distributing the code with the GPL.
    4. the author then reissues the exact same code with a fee-based 

What does this mean? It means that the GPL is a nice hedge for an author 
or organization who wants to reserve the exclusive right to commercially 
sell the software at some future point without competition."

This argument is expanded on in some detail; but relies on two 
misinterpretations of the GPL:

1. An author is certainly free to sell his/her code while it is under 
the GPL.  As is anyone else, there simply is no "right to sell the code 
exclusively" in the GPL, see above.

2. As the copyright holder, I believe the author is certainly free to 
change his/her license with a future release -- regardless of whether 
the code had changed.  But even if all reference to the GPL were removed 
from the future release, that would not revoke earlier releases' GPL 
licenses;  anyone who cared to could fork a GPL release and continue 
development provided they used the GPL license.  Thus the GPL achieves 
the one thing the author of this article attributes as the benefit of 
the MPL: a free market incentive to keep software free.

His next argument is with the "viral" nature of the GPL, but his first 
point supporting the argument is not true:

"First, it prevents the use of code released under other Open Source 
licenses, with the exception of Public Domain, from being used in 
combination to create a larger work. For example, suppose that you have 
located a third of the source code components that you need for your 
project under the GPL, another third under the X consortium/MIT style 
licenses, and the final third as Public Domain. Problem solved? No, you 
will either have to rewrite the GPL or the X consortium/MIT components 
as GPL will not co-exist with the other."

 From the top of

"We classify a license according to certain key questions:

     * Whether it qualifies as a free software license.
     * Whether it is a copyleft license.
     * Whether it is compatible with the GNU GPL. (This means you can 
combine a module which was released under that license with a 
GPL-covered module to make one larger program.)"

In fact his X11/MIT example is listed as compatible with the GPL on that 
page; I can't say whether this has changed since 1999, when this article 
was written, but it is clearly wrong today.

Last he complains that the GPL effectively creates a gulf between 
proprietary developers and FOSS developers... this certainly was an 
issue for a lot people in 1999, but I don't consider it important enough 
anymore to bore the list further

btw, I am a big fan of Mozilla, & had never bothered to read up on their 
license.  I see a version 1.1 (which presumably came out since that 
article was written) can, under certain conditions be compatible with 
the GPL -- at least according to the FSF:

"MPL 1.1 has a provision (section 13) that allows a program (or parts of 
it) to offer a choice of another license as well. If part of a program 
allows the GNU GPL as an alternate choice, or any other GPL-compatible 
license as an alternate choice, that part of the program has a 
GPL-compatible license."

I certainly don't believe that the GPL is best for everyone, and if your 
main issue with the GPL is its viral nature, the MPL looks like it may 
be a good alternative, after the LGPL & X11 licenses

of course,


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