Up until we hired a guy with MasterCam experience, one outfit I worked for used exclusively G-Zero, by Rapid Output. Thousands of part numbers. I don't remember the cost, but I don't believe it was terribly expensive.
I'm no programmer, but I sat in with them a bit and wrote a few programs for lathe and mill. I didn't find it too intimidating. But I'm sure it has changed. That was about 1988-89.
Scientists have shown that the moon is moving away at a tiny yet measurable distance from the earth every year. If you do the math, you can calculate that 85 million years ago the moon was orbiting the earth at a distance of about 35 feet from the earth's surface. This would explain the death of the dinosaurs. The tallest ones, anyway.