Is there a Mac OS X Terminal version of the "free" command in Linux systems?

As @khedron says, you can see this info in Activity Monitor. If you want it on the command line, here is a Python script that I wrote (or perhaps modified from someone else's, I can't remember, it's quite old now) to show you the Wired, Active, Inactive and Free memory amounts: #!/usr/bin/python import subprocess import re # Get process info ps = subprocess.Popen(['ps', '-caxm', '-orss,comm'], std