[GiNaC-list] sympy is NOT a derived work

[Ondrej Certik]

On Jan 1, 2008 5:44 PM, Alexei Sheplyakov <varg at theor.jinr.ru> wrote:
> Hello!
>
> On Tue, Jan 01, 2008 at 02:24:33PM +0100, Ondrej Certik wrote:
>
> > and there we also discussed sympy and ginac and licensing issues
> > and we came to the conclusion, that just by copying a C++ code
> > to Python (by hand) is a derived work.
>
> Disclaimer:
> IANAL, you should consult a lawyer to get a definitive answer.
>
> AFAIK, looking at the code and re-implementing the algorithm counts as
> a reverse engineering (GPL does NOT forbid it), and it does not make your
> code a derived work. Moreover, the algorithms in question are described in
> virtually any textbook on the symbolic computations. So, I think it is OK

We discussed that pretty thoroughly at the Sage workshop - and I think
when you look at a code and translate it line to line to another language,
it's a derived work. But anyway, I just wanted a confirmation, that
you are ok with this. (I think now, SymPy is not derived work anymore,
but it used to be).

> to use whatever license you like. That said, I don't think BSD one is
> a good choice (it will certainly distract some potential contributors),
> but that's a matter of my personal preferences.

It will distract some but bring some other ones. For example
if you look into the sympy mailinglist, you will see that some people find
ginac to restrictive, that it's GPL. On the other hand,
I also don't like, that Mathematica, a non-free program, is using GMP,
while giving nothing back.

>
> >we decided to use BSD, because it's more free
>                         ^^^^^^^^^^^^^^^^^^^^^^
> Could you please refrain from claims like this? Pretty *please*.

Sorry about that, I should have written:

we decided to use BSD, because we arrived at a consenus,
that BSD is more free (but other people may think otherwise).

Is that ok? :)

Ondrej