RepRapWiki. TEDxEWB Talk: Adrian Bowyer at Imperial College, London, introduces RepRap RepRap is humanity's first general-purpose self-replicating manufacturing machine.
RepRap takes the form of a free desktop 3D printer capable of printing plastic objects. Since many parts of RepRap are made from plastic and RepRap prints those parts, RepRap self-replicates by making a kit of itself - a kit that anyone can assemble given time and materials. It also means that - if you've got a RepRap - you can print lots of useful stuff, and you can print another RepRap for a friend... CNC. Instructables really shines when it comes to CNC (computer numerical control) projects.
We've got instructions on how you can make your own CNC lasers, CNC mills, CNC foam cutters and even a CNC chocolate 3D printer! Build a CNC device for your shop and make something awesome like flat pack furniture, something tasty like laser cut steaks and cakes, or something beautiful like a physical Escher print. Two steps over, four steps down, cut, burn, deposit chocolate - it's CNC on Instructables. RepRapWiki.