引自官方：
The GNU 3DKit is currently not available and won't be for some time. The project is being redesigned and reimplemented completely as the focus for the framework changed radically over the last few
years. Instead of developing yet another OpenGL based scene graph API the new GNU 3DKit will become an object oriented graphics framework based on global illumination concepts which will use OpenGL only for preview capabilities. More information will be reveiled
as soon as the time is ready for it.