FreeCAD is an open-source parametric 3D modeler that allows users to design real-life objects of any size. It offers various features such as parametric modeling, 2D and 3D sketching, and support for multiple file formats. The software is highly customizable and extensible, making it suitable for a wide range of uses, including product design, mechanical engineering, and architecture. FreeCAD is available for Windows, Mac, and Linux, and its development is supported by donations and sponsorships.