Ah, sorry. I didn't see that you require it to be free. It is also not open source IIRC.

There is Fork. But sadly, it is not available for Linux. Git-fork.com

I don't have an answer to you but if you like this sort of discussions/topics, I highly recommend the book Behave by Sapolsky.

Psychedelics are.. greatest thing I have ever done. Though I wouldn't call them a ritual.