There are seemingly eight, described on the G3D web site; it's not clear if there's any natural progression through them.
- ArticulatedModel loads models from files in 3DS, IFS, and PLY2 formats. Creates a scene graph, uses 'Pixel Shader 2.0' and 'fixed function' pipelines, apparently.
- GLSL_Shader_Demo uses pixel and vertex shaders to make a 2D texture appear to have shape.
- VAR Demo demonstrates rendering using dynamic vertex arrays, static vertex arrays, and the 'traditional per primitive rendering'.
- MD2Model_Demo uses animated models from Quake 2.
- Collision_Demo as name indicates, this uses the collision detection features of G3D.
- Win32_Demo uses non-OpenGL Win32 routines to display a JPG.
- Cg_Shader_Demo appears to show different approaches to texture mapping with Cg. Bump mapping, per-pixel shading, and normal mapping.
- ASM_Shader_Demo using programmable hardware of ATi/nVidia's chips to manipulate a 3D model.