[CentOS] trying to understand OSS, GPL, BSD & other licensing model for software distribution.

Eduardo Grosclaude eduardo.grosclaude at gmail.com
Wed Oct 7 14:17:07 UTC 2009

On Wed, Oct 7, 2009 at 5:01 AM, Rudi Ahlers <rudiahlers at gmail.com> wrote:

> What I don't yet fully understand, is how do we license both versions
> of the same script, so that if a community member writes an addon for
> the free one, that other community members can benefit from it as
> well? And more specific, is it possible to "force" them to
> redistribute their code via our community network?

Just ask nicely, and they will come --if you run a usable and
attractive site or community network able to grow into the best free
market for all things 'your product'.

> I see this a lot, for example with Joomla - which is free and anyone
> can contribute extra addons, whether free or commercial back into the
> community.
> But they don't have a commercial version of the same project. So I
> want to know how do I license the commercial scripts with this in
> mind? i.e. if I license them as GPL, do I need to disclose the source
> code? Cause we're going to encrypt the additional commercial code of
> the software.

I would like to point out that Yes, if you release GPL code you have
to disclose the source *to those people you redistribute it to* (see
for instance http://www.gnu.org/licenses/quick-guide-gplv3.html, or
read the fine print in GPL). You are not compelled to make your
sources universally visible or return them to any source code pool or
distribution, in the same sense that you are not forced to publish
code you develop for inhouse use. If you charge money for your GPL
product, your customers may, however, disclose the source to the
public --but they may very well not feel like it, as they have already
paid for that code!

Consider a business model of having a free, core trunk of code, and
separately selling (under any compatible license) custom code to go
along with it. This custom code implements some different behaviour
which only makes sense to a given customer or a vertical market. Every
new code you release under this model (because of licensing
compatibility with the core trunk) has to be released with its source.
But this means some acquisition cost, and a business advantage, to
your customer. He will want to keep it for himself --he won't disclose
it. And you can continue with your selling it as if in a closed source

Eduardo Grosclaude
Universidad Nacional del Comahue
Neuquen, Argentina

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