CNC Code Shooter is a great value for the small price. The latest version has a greatly enhanced GUI as well as many fixes throughout the program.     

New version just released.  Click on the link in the menu bar to download. This will work on both 32 and 64 bit Windows Systems. 

CNC Code Shooter is primarily a machine code generator and CNC back plotter. It displays the tool path from G code. It can also show tools if they are described properly. When you create a program or open a sample you must make G Code to see tool path. This is convienent way to view toolpath after edits have been made to a program. Most Cad Cam programs do not show toolpath of G-code but only of session. It has some special functions that if needed are worth the price by themselves. Mill face round is one of them. In minutes you can generate a tool peth for milling a round stock with multiple passes. CNC CodeShooter also works on Linux computers, Mono is needed to run it. Mono can be downloaded for free