[Gtk-sharp-list] Re: AW: [Mono-list] Is it time for GTK# yet

Miguel de Icaza miguel@ximian.com
01 May 2003 11:02:49 -0400


> Also, why can't it be used in GPL software? The license is CPL, and if I am 
> linking from a GPL software to SharpWT, I can always except that library 
> (we are doing that today in #develop with various libraries). Legally 
> speaking this is fine. If you have religious problems with that, well...

I would like to clarify some licensing concerns.

The problem with mixing licenses is not of a religious nature, but a
real legal concern.

The legal concerns is whether the end user end user has the right to
mix the licenses.   

It might be fine for a particular project to say `We will accept
linking our GPL code with CPL code' like you are doing with Sharp
Develop.   Various projects do this. 

But if you are using someone else's code (you are porting it, you are
extending it, you are borrowing, cut-and-pasting, adapting, shrinking
down, etc), you do not have that right.  

For example, it would be illegal to distribute a version of Emacs, or
Gnumeric, or any other program that has a CPL-conflicting license that
linked with Swt.  The only way for it to be legal is for everyone of the
copyright holders to allow this new usage.

That is the problem with a conflicting license.  We had these same
issues with Mozilla and the MPL.  In the end, the Netscape team was able
to dual licensing their code base to work around this problem.  It would
not be a problem typically, but the GPL is a major license used in the
free software world, so special consideration to this license is

Couple of actions:

	* We could go back to IBM and request that they relicense their
	  code under CPL + LGPL.  This would be ideal.  It is not very
	  hard, but it requires people to actively email and contact the
	  developers and managers and explain the situation.

	  Plenty of corporations are very receptive and will do the
	  right thing (Sun triple-licensed OpenOffice for this reason,
	  Netscape is now dual licensed as well).

	* We could investigate whether a re-write of the code is
	  actually covered by the original copyright.

	  I used to believe that if you rewrite someone else's design,
	  it would be a derivative work (for example, porting from C to
	  Java), but some time ago, I remember reading that the
	  copyright applied to the particular creational work, and that
	  a rewrite would not be covered by the original licensor's

	  I was also surprised at that, and am not a lawyer, but it is
	  worth investigating, because since #WT is inspired by SWT, but
	  not a direct copy (as far as I understand, and I have not
	  compared the code bases, so take this into consideration) the
	  code might fall under a different license.

Moving forward, I would like to encourage the SharpDevelop team to
choose a license that would allow people to maximize code mixing.  The
LGPL or the X11 licenses would allow this, and we would avoid these
problems for future users (am thinking of the other various fine pieces
of work that have spun off from the SharpDevelop team).