I can make shapes in cad (I-deas) on the one end.  on the other end, I have a cnc miller and can fumble my way to getting the spindle to turn and table to move.  BUT! the software that came with the miller is very limited.  Is MACH III something that I could use to make code of complex line paths or surfaces which I could edit to run on my simple machine or client machines?  oh, and what do the "post processors" that are offered on Artsoft's website do.  Thanks!

Mach 3 is not a code generation tool, Mach 3 drives a machine tool by outputting step and direction pulses to the motor drive units.

Post processors are g-code generation scripts for cad/cam programs.

Graham.