This example is terribly out of date. There is no longer a

            GLCanvas canvas = GLDrawableFactory.getFactory().createGLCanvas( new GLCapabilities() );

call.

Besides outdated docs (no more Canvas object crated from Factory), I ran into a bigger problem that *might* be affecting you. I received a "Not Implemented Yet" exception when invoking createExternalDrawable().

So it could be that as usual, the Mac implementation is behind that of other platforms (like slimy Mr. Gates).