A few months ago, we started the integration of a new engine in zynthian. This time it was something special as it was the first zynthian engine integrated by somebody else (Mr. Holger Wirtz, aka @C0d3man) and it wasn’t a free software engine, but a commercial product, with a privative license. Somebody could think that this is not well aligned with the spirit of zynthian project, so … why to do it?