QuickDraw 3D, or QD3D for short, is a 3D graphics API developed by Apple Inc. (then Apple Computer, Inc.) starting in 1995, originally for their Macintosh computers, but delivered as a cross-platform system.
QD3D provided a high-level API with a rich set of 3D primitives that was generally much more full-featured and easier to develop than low-level APIs such as OpenGL or Direct3D. Below this was a cleanly-separated hardware abstraction layer known as RAVE that allowed the system to be ported to new hardware easily. On the downside, QD3D used a number of Apple-specific ideas about how 3D hardware should work, and initially performed poorly due to the lack of hardware acceleration.
Apple abandoned work on QD3D after Steve Jobs took over in 1998, and announced that future 3D support would be based on OpenGL.
Read more about QuickDraw 3D: QD3D, RAVE, Switch To OpenGL, Applications