I mentioned CHIRP before, recently here
. Getting to be decent software, but I have scrambled radios with it some time ago. I have it working on Mac OS X with some of my RT Systems cables. They use FTDI and Prolific chipsets but set custom VIDs and PIDs so you have to tweak kexts (Mac equivalent to Windoze drivers). CHIRP also works with Linux, which is where it really shines.