Comment Stereo Lithography (Score 1) 40
Stereo lithography has (had?) been used for decades to prototype various 3D parts for fit and interference, though it could not make structural parts, certainly not for high temperature applications.
3D printing is a newer iteration of this technology as used for part fit and interference testing. The ability to actually fabricate the final product vs. just making resin shape prototypes is the really cool potential of this technology. It's being done now, but it will interesting to see how ubiquitous this becomes. It will be something when you see these next to the CNC machines in machine shops.
But watching 5-axis CNC machines make stuff is just mesmerizing.