Bogusław Brandys wrote:

>
> With multi-license (and with GPL also AFAIK) there are some
> problems.Someone could for example take 'product' source code,polish
> ,add a new feature ,tool and sell all together *without* source code (or
> with source code only for registered buyers) as a better 'product'.
> I consider this to be "not fair", however legally it's all fine.
> I think current license prohibit such usage (Am I right?) which is good.
>

The GPL and MPL style licenses do not allow taking the code
private, except by the original developer. What you're
describing can happen with the less restrictive licenses -
BSD for example - and public domain code. Postgres uses a
license like that which is why their code can be repackaged
and sold without source code.

The GPL requires that any code that incorporates GPL code be
released as GPL. That clearly covers the case you describe,
and a number of other cases.

The MPL requires that changes to code licensed under MPL be
published. That allows somewhat more flexibility. For example,
if you were to build a version of Firebird that encrypted
database files, you would need to publish any changes you
made to the Firebird sources - interfaces to your code - but
not the new code you wrote. You can sell your original work,
without sources but you need to show everyone how you connect
that work to Firebird.

The original developer has the right to relicense code released
under GPL - and most other licenses. MySQL, for example, uses a
dual GPL and commercial license. If your application meets the
requirements of GPL - the whole thing is open source or the whole
thing is in-house - then you can use the GPL version for free.
If you want to resell a package that includes MySQL, you need to
license their commercial version. That's perfectly compatible
with the GPL license because MySQL owns the copyright to all
their code and can release it under any combination of licenses.

Regards,


Ann