FreeCAD is a general purpose parametric 3D CAD modeler, whose development is completely open source (LGPL License). FreeCAD is aimed directly at mechanical engineering and product design but also fits in a wider range of uses around engineering, such as architecture, finite element analysis, 3D printing, and other tasks.
FreeCAD features tools similar to Catia, SolidWorks or Solid Edge, and therefore also falls into the category of MCAD, PLM, CAx and CAE. It is a feature based parametric modeler with a modular software architecture which makes it possible to provide additional functionality without modifying the core system.
As with many CAD modelers it has many 2D components in order to sketch planar shapes or create production drawings. However, direct 2D drawing (like Inkscape or AutoCAD LT) is not the focus, neither are animation or mesh edition (like Blender, Maya, 3ds Max, or Cinema 4D). Nevertheless, thanks to its wide adaptability, FreeCAD might become useful in a much broader area than its current focus.
FreeCAD makes heavy use of open-source libraries that exist in the field of scientific computing. Among them are Open Cascade Technology (OCCT), a powerful CAD kernel; Coin3D, a toolkit for 3D graphics development compatible with Open Inventor; Qt, the world-famous user interface framework; and Python, a modern scripting language. FreeCAD itself can also be used as a library by other programs.
FreeCAD is also multi-platform, and currently runs on Linux/Unix, Windows, and Mac OSX systems with the same look and functionality on all platforms.
About the FreeCAD project
The FreeCAD project was started as far back as 2001, as described in its history page.
FreeCAD is maintained and developed by a community of enthusiastic developers and users (see the contributors page). They work on FreeCAD voluntarily, in their free time. They cannot guarantee that FreeCAD contains everything you might wish, but they will do their best! The community gathers on the FreeCAD forum, where most of the ideas and decisions are discussed. Feel free to join us there!