FreeCAD is a parametric 3D modeler. Parametric modeling allows you to easily modify your design by going back into your model history and changing its parameters. FreeCAD is open source (LGPL license) and completely modular, allowing for very advanced extension and customization.
Blender is being made by hundreds of active volunteers from around the world; by studios and individual artists, professionals and hobbyists, scientists and students, VFX experts and animators, and so on. All of them are united by the desire to have access to a fully free/open source 3D creation pipeline.The Blender Foundation supports and facilitates these goals – even employs a small staff for that – but depends on the online community to achieve this goal. More help is always welcome!