From octave-graphics-request at bevo dot che dot wisc dot edu  Fri Aug 25 01:31:30 2000
Subject: Re: is VTK the license octave compatible ?
From: "John W. Eaton" <jwe at bevo dot che dot wisc dot edu>
To: Kai Habel <kahacjde at calvados dot zrz dot TU-Berlin dot DE>
Cc: octave-graphics at bevo dot che dot wisc dot edu
Date: Fri, 25 Aug 2000 01:29:37 -0500 (CDT)

On 24-Aug-2000, Kai Habel <kahacjde at calvados dot zrz dot TU-Berlin dot DE> wrote:

| Kai Habel wrote:
| > 
| > Hello,
| > 
| > I have the impression that the license for VTK has changed this year.
| > The question: is the license below octave(GPL) compatible? I fear the
| > last point might be a problem.
| > 
| > Copyright (c) 1993-2000 Ken Martin, Will Schroeder, Bill Lorensen
| > All rights reserved.
| > 
| > Redistribution and use in source and binary forms, with or without
| > modification, are permitted provided that the following conditions are
| > met:
| > 
| > * Redistributions of source code must retain the above copyright notice,
| > this list of conditions and the following disclaimer.

OK.  The GPL also requires this.

| > * Redistributions in binary form must reproduce the above copyright
| > notice,
| > this list of conditions and the following disclaimer in the
| > documentation
| > and/or other materials provided with the distribution.

Fine.  No more restrictive than the GPL, which would require source
too (or an offer to provide it).

| > * Neither name of Ken Martin, Will Schroeder, or Bill Lorensen nor the
| > names
| > of any contributors may be used to endorse or promote products derived
| > from this software without specific prior written permission.

I don't think this is a problem.

| > * Modified source versions must be plainly marked as such, and must not
| > be
| > misrepresented as being the original software.
| > ...

This is not a problem either.  The GPL also says

    2. You may modify your copy or copies of the Program or any portion
  of it, thus forming a work based on the Program, and copy and
  distribute such modifications or work under the terms of Section 1
  above, provided that you also meet all of these conditions:

      a) You must cause the modified files to carry prominent notices
      stating that you changed the files and the date of any change.

so I think this requirement is fine too.

| Assuming the license is ok, wouldn't vtk a very good candidate for
| ocatve's graphics?

Yes.  I heard about it several years ago, but then it was not
distributed under terms that were compatible with the GPL.  Thanks for
pointing out the new license.

Now, who would like to write the code necessary to allow it to be used
from Octave?  :-)

jwe