FreeCAD

FreeCAD is a parametric 3D computer-aided design (CAD) modeler built for product design, mechanical engineering, and architecture. It features a modular architecture with specialized workbenches for 2D drafting, 3D solid modeling, finite element analysis (FEA), and CAM/CNC code generation. It reads and writes standard formats like STEP, IGES, STL, and DXF.