I just happened to read the following about gnuplot in the gnuplot FAQ:
Gnuplot is neither written nor maintained by the FSF. It is not covered
by the General Public License, either. It used to be distributed by the
FSF, however, due to licensing issues it is no longer.
Gnuplot is freeware in the sense that you don't have to pay for it.
However it is not freeware in the sense that you would be allowed to
distribute a modified version of your gnuplot freely. Please read and
accept the Copyright file in your distribution.
Which surprised me, so I'm sending this to the list to be sure that
everyone is aware of it. I had always assumed that gnuplot was a GNU
product and distributed under the GPL.
Mike
-------------------------------------------------------------
Octave is freely available under the terms of the GNU GPL.
Octave's home on the web: http://www.octave.org
How to fund new projects: http://www.octave.org/funding.html
Subscription information: http://www.octave.org/archive.html
-------------------------------------------------------------