Avogadro libraries provide 3D rendering, visualization, and analysis
The open-asset-importer-library repository
GLScene Engine for Delphi & C++Builder VCL Windows 32/64
Realtime raytracer using SIMD on ARM, MIPS, PPC and x86
Interactive 3D Layout Viewer for GDSII
Tiny but powerful single file wavefront obj loader
3D File format viewer/explorer
ITK-SNAP static builds for Windows 64-bit(only one file)
Pear3DEngine is a modern and modular 3D development framework
PixelLight is a cross-platform application framework
osGraphX is a 3D file viewer based on openscenegraph.