The Free Universal Construction Kit

F.A.T. Lab and Sy-Lab released the Free Universal Construction Kit, a set of nearly 80 3D-printable adapter bricks enabling interoperability between 10 popular children's construction toys including Lego, Duplo, K'Nex, Tinkertoys, and others. The adapters are available as free STL files on Thingiverse, reverse-engineered with optical comparator precision. The project frames itself as a civic act of reverse engineering — analogous to VLC for video formats — challenging proprietary lock-in in physical consumer products. Licensed under CC BY-NC-SA 3.0, it permits personal fabrication but prohibits commercial mass production to avoid contributory patent infringement liability.