FreeCAD 3D CAD Modeler

FreeCAD is a free and open-source parametric 3D CAD (Computer-Aided Design) modeler designed for mechanical engineering, product design, and architecture. Originating in 2001 by Jurgen Riegel and maintained by a global community, FreeCAD has become the leading open-source CAD application. Key features: parametric modeling where all geometry is driven by parameters (dimensions, constraints, expressions), enabling easy modification and iteration of designs by changing parameter values. Modular workbench architecture with specialized workbenches including Part Workbench (B-rep solid modeling via OpenCASCADE), PartDesign Workbench (feature-based parametric solid modeling with sketches, pads, pockets, and revolutions), Draft Workbench (2D drafting), Arch Workbench (BIM and architecture), Mesh Workbench (STL mesh creation and editing), FEM Workbench (finite element analysis), Path Workbench (CAM and CNC machining), Assembly Workbench, and Render Workbench. Sketcher with geometric constraints (coincident, parallel, perpendicular, tangent, horizontal, vertical) and dimensional constraints (distance, angle, radius) for fully parametric 2D profiles. Constraint solver for maintaining design intent. OpenCASCADE-based geometric kernel for robust B-rep solid modeling, boolean operations, fillets, chamfers, and sweeps. Import and export to STEP, IGES, STL, OBJ, DXF, DWG, SVG, COLLADA, and IFC formats. Python scripting API for automation, custom workbenches, macros, and plugins, making FreeCAD highly extensible. Assembly solver for multi-part assemblies with mate and alignment constraints. Drawing generation for creating 2D technical drawings from 3D models with dimensions, annotations, and title blocks. FEM analysis with CalculiX solver for stress, thermal, and vibration analysis. CAM for generating G-code for CNC machining. Cross-platform on Windows, macOS, and Linux.