Open-source Autodesk Fusion alternatives

FreeCAD is a parametric 3D modeling application for designing physical objects of any size. Parametric modeling means you can change a design by editing parameters in its model history. It can create 3D shapes from constrained 2D sketches and produce production drawings from the resulting 3D models. FreeCAD is released under the LGPL-2.1 license and written mostly in C++.

The software suits hobbyists, programmers, experienced CAD users, students and teachers working on product design, mechanical engineering and architecture. Related topics on the project include BIM, FEM, CAM, civil engineering and 3D printing. It builds on the OpenCASCADE geometry kernel, the Coin3D scene library, a Qt interface and a broad Python API for scripting. Precompiled packages for Windows, macOS and Linux are available from the releases page, and many Linux distributions include it in their software centers.

OpenSCAD is free software for creating solid 3D CAD objects, available for Linux and UNIX, Windows and macOS. It concentrates on the CAD side of 3D modeling rather than the artistic side, which makes it a fit for machine parts and engineering objects but not for computer-animated films.

It is not an interactive modeler. Instead it works like a 3D compiler that reads a script describing the object and renders the model from it. That gives designers full control over each step and makes it easy to change parameters or produce configurable designs. The two main techniques are constructive solid geometry and extrusion of 2D outlines, and it can read and write DXF, STL and OFF files.

The program is written in C++ with Qt and OpenGL, and the README explains building from source on macOS, Linux, BSD and Windows. When you open the app, the window shows three frames, including a script editor on the left. Its license is stated in the repository, and binaries can be downloaded from the project website.