Not really the infancy, more like the case of PCs/Macs whatever were the first time computers got into the home, the technology has just become more affordable for a variety of reasons for anybody to do it in their own home or in small businesses. This type of technology is well over 20 years old more like 30 plus, and has been used to rapid prototype many mechanical parts. I remember seeing it for the first time in the late 80s maybe early 90s used for making prototype missile parts, straight from CAD, something that would have been much more involved to do in a CNC setup, probably couldn't even have been done in one piece that way.