zMol is a library for displaying molecular data in a 3D canvas, using ambient occlusion as described in the paper "Ambient Occlusion and Edge Cueing to Enhance Real Time Molecular Visualization" , 2006 by Tarini et al. An existing (but abandoned) implementation called QuteMol exists.

Of all the classes, molecule_data and molecule_renderer are the ones that are of interest to application developers. The remaining ones are internals.
However, application developers need to initialize gl3w (the OpenGL 3 extension handler library used by zMol). Calling gl3wInit() right after initializing the OpenGL context is sufficient.