SheepIt Render Farm - A free distributed render farm for Blender
Unity - The multiplatform game creation tools for everyone.
TurboRender - Rendering at your workstation?
Godot Engine - Feature-packed 2D and 3D open source game engine.
RebusFarm - RebusFarm is a 3D rendering software.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.