FreeCAD - An open-source parametric 3D modeler
Unity - The multiplatform game creation tools for everyone.
VARKON - Varkon is a very powerful parametric 2D/3D CAD, modeling and application development tool for...
Godot Engine - Feature-packed 2D and 3D open source game engine.
ArCADia-Architecture - ArCADia-Architecture is a revolutionary component for the instant creation of architectural documentation and object drawing.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.