Way back when I got into cnc, it was still EMC (Not EMC2) and there was no BDI (brain dead installation) CD. Mach1 was out and I still used win98. So I looked at Turbocnc which is dos based and at the time if one registered ($20) you got the source code. I figured it would do what I needed at the time and who knows, maybe I could learn enough programing to add a feature or two along the way if development ever stopped. I never have trusted windows for a control application and that also figured into my decision. Now many years down the road, it is like an old coat and I am comfortable with it and will continue to make that my mainstay controller.