Open Source Solid Modeling CAD
3d library worte in C with Gtk+
Cross-platform open source software for astrophotography
Electromagnetic Analysis Software
A 3d rendering framework
A really simple (following K.I.S.S statement) ray tracing project.
3D game engine for C and C++
A complete movie editor for animations and special effects
An easy way to check and discard your blurry images.
A 3D rendering / entity engine
3D Engine technology with partial tools developing kit.