Slic3r is free software 3D slicing engine for 3D printers. It generates G-code from 3D CAD files (STL or OBJ). Once finished, an appropriate G-code file for the production of the 3D modeled part or object is sent to the 3D printer for the manufacturing of a physical object. As of 2013, about half of the 3D printers tested by Make Magazine supported Slic3r.