Brian Fox writes:
> If the price is very low, is that close enough to "free"?
>
> The extreme case that comes to mind is KCL.  You are not allowed to
> use the product without a license, but you can get a license
> (including source license) just for asking.

And Christopher Maeda writes:
> I see little *practical* difference between free software and
> inexpensive proprietary software that comes with source code...

Let me give my perspective, as a consumer of software.  When I was
looking for a Lisp to program in, I never tried KCL, because of the
hassle of getting a license.  I tried a bunch of free Scheme
implementations, found several which did what I wanted, and now use
SCM regularly.

A proprietary program has to provide functionality that can't be found
somewhere else, whether it costs $0 or $1000.  If I had needed to run
Common Lisp programs, I would have tried KCL, but I didn't.

A free program can travel with solutions that I create.  This is
important.  For example, a group in Colorado we were working with
asked for some help in converting some documentation into a special
format, which they had been doing by hand.  I put together a twenty
line Emacs-lisp function that called out to a ten line Perl script to
help automate the task.  They didn't have Perl, but that was OK
because I just stuck it in with the rest of the package.

A proprietary program drives up the hassle factor.  I have to sign
forms and place orders or whatever, just to find out if it will do the
job.  Then whoever I'm providing the solution to has to do it over
again, to get their copy.

In summary, a free program which does the job will win out over a $0
proprietary program, even if it comes with source code.

Andrew Wilcox
Department of Astronomy & Astrophysics, Pennsylvania State University
(awilcox@astro.psu.edu)