The Ornament & Crime is one of the most succesful open-source and DIY projects in the eurorack world. The organizers of the workshop at Common Ground advertise the workshop with these words:
“After one year and a successful workshop, Common Ground decided to host another building workshop of the great Ornament & Crime eurorack-module, a collaborative open-source project by mxmxmx, Patrick Dowling, and Tim Churches. The module is available as DIY-only and all the parts on the board are (reasonably-sized) SMD so this is a great change to start learning those SMD-soldering skills. The workshop is organized in agreement with mxmxmx, the original designer.”
More info here.