CAMotics is an Open-Source software which simulates CNC milling or engraving. It is a fast, flexible and user friendly simulation software for the DIY and Open-Source community. CAMotics works on Linux, OS-X and Windows.
If you have Linux, or want to use a Linux based CNC control software, is a great option. is a very powerful and full featured CNC control software that features a large viewing are, simple configuration and control panel.