Do you mean the one I used?
I used Absynth. It's from 2000. I recorded all the samples in Mac Os 9 then migrated them to another computer to mix it. You can get some decent and unique sounds from it. Would be much easier using something newer. I only used it because I had the gear ready to go. I've made every soundtrack this way. If I were to do this again I'd use a more modern program or just use a real synth.