Subject: Re: Which DUAL Licence should I choose.
From: John Cowan <>
Date: Fri, 29 Jul 2011 17:12:16 -0400

Thomas Schneider scripsit:

> I do have some partner's around the world who might be interested to
> CONTRIBUTE to my software. In order to be able to do so, I would like
> to OPEN SOURCE the Software on KENAI, but SELL it !

Open-source licenses don't prevent you from selling software: in fact,
they encourage it.  Which means that anyone can sell your software, not
just you.

Your advantage, however, is that you know the software much better than
any competitor would.  So if a user wants a change in the software,
you can offer your services in customizing it for money.  It's up
to you and your customers whether you add the customizations to the
open-source version or not.  Anyone else could do the same thing, but it
would probably be harder for them and slower to get done, so you have a
commercial advantage.

Some programmers do this systematically by releasing version N of the
software only under a proprietary license, while versions N - 1, N
= 2, etc. are all open source.  

John Cowan
'Tis the Linux rebellion / Let coders take their place,
The Linux-nationale / Shall Microsoft outpace,
We can write better programs / Our CPUs won't stall,
So raise the penguin banner of / The Linux-nationale.  --Greg Baker