FreeCAD is a free and open-source (under the LGPLv2+ license) general-purpose parametric 3D CAD modeller and a building information modelling (BIM) software with finite-element-method (FEM) support. FreeCAD is aimed directly at mechanical engineering product design but also expands to a wider range of uses around engineering, such as architecture or electrical engineering. FreeCAD can be used interactively, or its functionality can be accessed and extended using the Python programming language and is currently in a beta stage of development.

FreeCAD features tools similar to Autodesk Revit, CATIA, Creo, Autodesk Inventor, SolidWorks or Solid Edge, and therefore also falls into the category of Building Info Modelling (BIM), Mechanical computer-aided design (MCAD), PLM, CAx and CAE. It is intended to be a feature-based parametric modeller with a modular software architecture, which makes it easy to provide additional functionality without modifying the core system.

As with many modern 3D CAD modellers, it will have a 2D component in order to extract design details from the 3D model to create 2D production drawings, but direct 2D drawing (like AutoCAD LT) is not the focus, neither are animation or organic shapes (like Blender, Maya, 3ds Max or Cinema 4D), although, thanks to its wide adaptability, FreeCAD might become useful in a much broader area than its current focus.

FreeCAD is intended to make use of other open-source libraries from the field of scientific computing. Among them are Open CASCADE (a CAD kernel), Coin3D (an incarnation of Open Inventor), the Qt GUI framework, and Python, a popular scripting language. FreeCAD itself can also be used as a library by other programs.

There are moves to take FreeCAD into the architecture, engineering and construction (AEC) sector and add building information modelling (BIM) functionality with the Arch Module.

For more information:

https://en.wikipedia.org/wiki/FreeCAD