3D Without Boundaries
FlightGear Flight Simulator: free open-source multiplatform flight sim
An interactive viewer for three-dimensional chemical structures.
Interactive 3D Layout Viewer for GDSII
rayshade and POV for Mathematica Export + view
Python 3D renderer with wireless display support
Viewer and exporter for Unreal Engine 1-4 assets
Tao3D is a programming language for real-time interactive 3D
PyMOL is an OpenGL based molecular visualization system
Highly accurate ray-tracing software system for UNIX computers
3D Charts - Templates for PovRay(TM)
Program for drawing 3D surfaces from parametric equations
XNA based game engine completely written in c#
Interactive visualization of DTI, HARDI and other complex imaging data
Pear3DEngine is a modern and modular 3D development framework
PixelLight is a cross-platform application framework
A home-base for Lego Hobbyists.
A 3D rendering / entity engine