Ferret--Mac users,3) Install pyferret exactly as described in the official guide https://ferret.pmel.noaa.gov/Ferret/downloads/ferret- .installation-and-update-guide After that, I installed pyferret on another macOS High Sierra machine of mine, which failed to work. This problem seems to be due to the lack of 100% binary compatibility (perhaps due to dependency on hardware) in some of the pyferret dynamic libraries.Then in a private email exchange, Karl pointed me to another method of installation: https://github.com/NOAA-PMEL/PyFerret/blob/master/README.md , which worked! I list the revised steps:0.1) Install homebrew.0.2) Install python via homebrew.1.1) Install miniconda via homebrew:$ brew install miniconda1.2) Add "/usr/local/miniconda3/bin" in your search path. (Search the Net for how to add a search path.) Note that currently "miniconda" means "miniconda3" on homebrew. This may change in the future.2) As in README.md$ conda create -n FERRET -c conda-forge pyferret ferret_datasets --yes3) If you are familiar with the notion of the conda "environment" or if you want to familiarize yourself with it, follow the instruction in README.md and ignore this step. If you don't care about the conda environment, you may want to create a shell script like the following and call it "pyferret" or whatever you like:#!/bin/shCONDABASE=/usr/local/miniconda3 source $CONDABASE/bin/activate FERRETexec $CONDABASE/envs/FERRET/bin/pyferret "$@" and you use this script in place of the real pyferret command.I think this is all.Cheers,Ryo-------Aside: Currently it's hard for me to use the conda environment because it needs to add variables to your shell and hence works only on Bourne shells or cshells, whereas I use a shell called "fish", which isn't POSIX compliant.