Today, futurists who speak of "post-scarcity" suggest economies based on advances in automated manufacturing technologies,[4] often including the idea of self-replicating machines, the adoption of division of labour[9] which in theory could produce nearly all goods in abundance, given adequate raw materials and energy. More speculative forms of nanotechnology (such as molecular assemblers or nanofactories, which do not currently exist) raise the possibility of devices that can automatically manufacture any specified goods given the correct instructions and the necessary raw materials and energy,[10] and so many nanotechnology enthusiasts have suggested it will usher in a post-scarcity world.[11][12] In the more near-term future, the increasing automation of physical labor using robots is often discussed as means of creating a post-scarcity economy.[13][14] Increasingly versatile forms of rapid prototyping machines, and a hypothetical self-replicating version of such a machine known as a RepRap, have also been predicted to help create the abundance of goods needed for a post-scarcity economy.[15] Advocates of self-replicating machines such as Adrian Bowyer, the creator of the RepRap project, argue that once a self-replicating machine is designed, then since anyone who owns one can make more copies to sell (and would also be free to ask for a lower price than other sellers), market competition will naturally drive the cost of such machines down to the bare minimum needed to make a profit,[16][17] in this case just above the cost of the physical materials and energy that must be fed into the machine as input, and the same should go for any other goods that the machine can build.