To run the OS X version, you need to install the RXTX serial and parallel I-O libraries. An installer is included. On an iMac you need a USB-Serial converter. When you use the KEYSPAN USA-28X, a special cable to connect the DMM to the Mac needs to be constructed. Here's a writeup by Jeff Luszcz , the author of MacMultimeter, on making a patch box so that any serial cable works with it.
This demo version can do 10 readouts per run, you need to register for the full function version.