I am looking at the SmoothStepper. What other options are available for USB control under Mach3?

I will be starting my project using MACH3 to control a mill and a lathe. I would like an interface option which could eventually be usable under EMC, and finally by my controlling it directly at the USB level using custom software running under OSX.

- George Lawrence Storm • Maltby, Washington

EMC doesn't support any USB devices, so that's not an option.
The Dynomotion KFLOP is another USB option for Mach3.