Do-it-yourselfers have made everything from bamboo bicycles to 3-D printers, but nothing as ambitious as the Open Source Ecology project. On a farm in northwest Missouri, tractors and other industrial machines are made from scratch, with detailed plans on how to do it yourself shared online.
http://www.npr.org/2012/02/19/147110017/building-a-village-one-home-brewed-tool-at-a-time&ft=1