Quesa

From Purple Shark Software:

Quesa is a high level 3D graphics library, released as Open Source under the LGPL, which offers binary and source level compatibility with Apple's QuickDraw 3D API. Quesa does not contain any Apple source code, and was developed without access to Apple's QD3D implementation. QD3D supports both retained and immediate mode rendering, an extensible file format, plug-in renderers, a wide range of high level geometries, hierarchical models, and a consistent and object-orientated API. Quesa can sit on top other lower-level APIs (such as OpenGL or Direct3D), and provide the 'scene graph' level of organisation that these APIs typically lack.