Prerequisites
From CHARMM tutorial
Prerequisites for this tutorial
This tutorial assumes that you have login ability to a Unix machine (this includes MacOS X). We further assume that CHARMM is already installed on this machine and you know the command to invoke it. If you just received the CHARMM distribution and need help installing it, here are some installation instructions.
Since CHARMM is a command line program, you need some familiarity with the Unix shell (the Unix command line), even on MacOS X! You should be able to navigate the directory hierarchy, copy and move files, and know how to use a text editor. At the time of writing this tutorial, one good Introduction to the Unix command line can be found here; should this link be broken google for something like "introduction to the unix command line".

