On Oct 23,  9:50pm, Thomas Mondoshawan Tate wrote:

> On Tue, Oct 23, 2001 at 04:22:39PM -0700, Kevin Buettner wrote:
> >
> > You can still do the same thing with the GPL so long as you are the
> > copyright holder.  You can release a piece of software under the GPL
> > and reap all of the usual benefits from doing so.  But you, the
> > copyright holder, may also license this software to others (for
> > commercial gain, etc.) under some other license which doesn't have
> > the same restrictions as the GPL.  (I.e, the licensee won't be forced
> > to redistribute his propriety changes.)
> 
> Aahh... But there is a slight problem -- wouldn't the viral effect of the
> GPL come into play here and prevent me from doing so? (referring to the
> clause that states all derivations of the product under the GPL must be
> under the GPL)

No.  So long as you are the copyright holder, you can choose which
licenses apply to your software.  You can do a GPL'd source code
release and custom licenses for anyone that wants to make use of
your code without having to comply with the GPL's restrictions.

Here are several examples:

    Ghostscript
	- latest free (as in beer) versions licensed under terms which
	  prevent commercial use.  Commercial use versions also available
	  for a fee.
	- also licensed under the GPL, but these versions are somewhat
	  older.  (If the latest release is N, the GPL release is
	  usually N - 1.)

    Perl
	- Dual licensed under GPL and Artistic License.

    Mozilla
	- Tri-licensed under NPL, GPL, and LGPL.  (Though I think work
	  is still underway to get all of the source code to comply
	  with the latter two.)

    Cygwin (library)
	- Dual licensed under the GPL and a proprietary-use license
	  (available for a fee) if you want to port a proprietary
	  application which uses the Cygwin library.

Of these examples, the licensing schemes used by Ghostscript and
Cygwin merit the most study since they are closest to what you want to
do.  (You can find out more about these programs and their licenses by
using Google.)

Kevin