First of all, I want to thank you for all your advices in this forum. Since yesterday, I try to get it working on my Mac (running OS 10.11). I finally managed to make downloaded m-psarc files work. But what doesn't work yet, is the RSCustomSongToolkit. When launching it, it only tells me to download the latest Mono framework. I did it and installed it, but when running the Toolkit again, it tells me again to install Mono. I tried it another time (now both version are being tried: the universal and the 32 bit), but nothing changes. Do you have any ideas about this issue? Thanks in advance!