PHIGS (Programmer's Hierarchical Interactive Graphics System)
simple 3d scene viewer for windows/linux/android
Semiautomatic generation of semantic building models from image series
an interactive 3D viewing program
Gimpel3D - 2D/3D Stereo Conversion Editor
3D game engine for C and C++
A small library to create SDL 2 - OpenGL applications.
Pear3DEngine is a modern and modular 3D development framework