I am working at Minatec in Grenoble. and we have all the license for
the cadence environment in which I developed my code.
The code is completely developed by myself, and I am preparing a paper
to publish it work in an international conference (ieee IDT maybe).
The users of my code should have a cadence license ( which is normal
for all cadence users, there's no cracked version for cadence- you can
search online and you will not find).
I tested my Interface, and it support not only the ngspice but any
other free spice simulator.
In addition, I created a project and i will put it on my page, but i
am interested also to share my work with the ngspice project, so we
take a look on my page : https://sourceforge.net/projects/imepspiceinterface/
it's under construction. I will updated ( added the code, and all the
information needed to install the interface).