Dual-Licensing Situation

[seventh guardian]

On Tue, Jun 10, 2008 at 3:45 PM, AR <aricvim at suddenlink.net> wrote:
> maillistaddress at paulbanks.org wrote:
(...)
>> They write, "Trolltech's commercial license terms do not allow you to
>> start developing proprietary software using the Open Source edition."
>>
>> In this case, it does indeed appear to prevent you from doing what you
>> want to do: i.e. start a commercial project based on code developed with an
>> open source edition. But as far as I can tell, whilst that's perhaps against
>> the spirit of free software* and of questionable morality, it's not a
>> violation of any license. They're free to license their own stuff (or not)
>> on whatever terms they want to.
(...)
> I'm glad you're seeing my point, but it is more than a sour taste in the
> mouth.  It appears I am barred from obtaining the proprietary license and
> dual-licensing my code to someone who wants to buy it and pay me royalties
> for it solely because I accepted the GPLv2, without any mention in the terms
> of the license that that is the case.

I believe they want to prevent opportunist people from _distributing_
the GPLv2 version before they buy the license.

I guess you can start developing the software in your private
repository from the GPLv2 sources before you buy the proprietary
license, as long as you don't publish it. They obviously can't "prove
without any doubt" that you were working on it before buying the
license.

This prevents the scenario where a developer starts
developing/publishing a GPLv2 free software and then closes its source
and sells it when/if it is successful enough. Or abandons the project
if it is not successful, and doesn't pay Trolltech. However, if you
are a serious commercial software developer, then you will want to
sell your final software, and you'll buy the license.

If you start releasing GPLv2 you cannot then close the source (that
is, switch to the proprietary license). Even if the proprietary
license says you can release GPLv2 code, you can still opt not to. So
it may actually present a benefit to the open source spirit. Probably
the wording should be revised, but that's it..

As for profiting from the software, you can always sell support. No
one in his perfect judgement would buy the commercial version if it
was no different from the open source one. People buy support, and
that has nothing to do with the license you choose.

Cheers,
  Renato Caldas