Mach3
From CNC.xyz Wiki
Mach3 is one of the most popular commercial CNC programs available for hobbyist and professional CNC machines alike. It is one of the most fully featured CNC software packages available, with a large user base and support community.
Mach3 turns a typical computer into a CNC machine controller. It is very rich in features and provides a great value to those needing a CNC control package. Mach3 works on most Windows PC’s to control the motion of motors (stepper & servo) by processing G-Code. While comprising many advanced features, it is the most intuitive CNC control software available. Mach3 is customizable and has been used for many applications with numerous types of hardware.[1]