FreeCAD

FreeCAD is a parametric 3D modeler for designing real-life objects of any size. Parametric modeling lets you change a design by stepping back through its history and editing the parameters that drive it, so dimensions and features update automatically.

You sketch geometry-constrained 2D shapes and use them as the base for 3D objects, then extract details or adjust dimensions to produce high-quality, production-ready drawings. It serves product designers, mechanical engineers, and architects alike, from hobbyists to students and seasoned CAD users.

FreeCAD is built on the OpenCASCADE geometry kernel, the Coin3D scene library, and a Qt interface, and it exposes a broad Python API for scripting and automating workflows. It runs on Windows, macOS, and Linux, with precompiled packages for each platform.