SKDB
SKDB' is a method for sharing hardware over the internet. It is under development by Ben Lipkowitz and Bryan Bishop, among others,. "Hardware" means not just designs for circuit boards, but also biological constructs, scientific instruments, machine tools, nuts and bolts, raw materials, and how to make them. SKDB simplifies the process of searching for free designs, comparing part compatibility, and building lists of materials and components and where to get them. You could even say SKDB is "apt-get but for real stuff". The SKDB project is a means of indexing, cross-referencing and building dependency-trees for hardware goods. Tell it you want to build a car, and it will give you a list of the necessary components and sub-components and list the tools required to make each one.