LinuxCNC (the Enhanced Machine Control) - LinuxCNC: an open source CNC machine controller. It can drive milling machines, lathes, 3d printers, laser cutters, plasma cutters, robot arms, hexapods, and more.
ECam - Nice, fast and intuitive. A 2D Cad/Cam designed for simple machining operation
Vectric Aspire - The complete software solution for CNC Routing,
FreeCAD - An open-source parametric 3D modeler
Mastercam - Mastercam's Dynamic Milling is a game changer for us.
PyCAM - PyCAM is a toolpath generator for 3-axis CNC machining.