Viewtiful is one of the demos that come with the Sc21 framework.

Due to popular request, and since there appears to be no decent VRML viewer on Mac OS X, we are packaging it as a stand-alone application. Since this is just a piece of sample code, don't expect full viewer functionality – but you might find Viewtiful useful to quickly look at Inventor and VRML files.

http://ftp.coin3d.org/coin/bin/macosx/Viewtiful.dmg

Enjoy!