The SMea Kit is an open-source, high-level 3D graphics library, written in Objective-C atop OpenGL and Mac OS X's Cocoa framework. It is designed to support virtual reality applications, in which multiple articulated human figures interact on an expansive landscape. However, many of the kit's components are quite general, providing functionality needed in any 3D program. You can mix and match classes as you like. You might also use the kit as a tutorial to help you get started with OpenGL. The SMea Kit manual is viewable online
. The download includes the SMea Kit and its demo program.