What is a post processor?
From PROBOTIX :: wiki
A post processor is a language definition file used to modify generic g-code such that it can be used on a particular cnc machine. They are just text files and can be opened and editied in notepad. They define inch vs metric, the file extension that the g-code is saved as, whether or not line numbering is used, the pre-amble and post-amble, and what each of different classes (rapid, feed, arc, etc) of moves looks like. Mach3, LinuxCNC, and the CNC USB Control Software can all use the generic g-code post-processors available with every CAM program.
We have post-processors available for: