The author can argue that OpenGL is not a 3D library. That argument would be wrong.<p>This is an old debate. Scene-graph APIs have been around for a long time, and include PHIGS and VRML. As <a href="http://en.wikipedia.org/wiki/PHIGS#The_rise_of_OpenGL_and_the_decline_of_PHIGS" rel="nofollow">http://en.wikipedia.org/wiki/PHIGS#The_rise_of_OpenGL_and_th...</a> comments, OpenGL requires tuning, but the end result can be much faster than the "automatic" tuning in PHIGS.<p>The three.js which the author points out is a scene graph library. There's no reason to restrict, as the author asserts, 3D graphics libraries to only scene graph libraries. <a href="http://en.wikipedia.org/wiki/List_of_3D_graphics_APIs" rel="nofollow">http://en.wikipedia.org/wiki/List_of_3D_graphics_APIs</a> categorizes them correctly as low-level and high-level 3D libraries.