Jarfish Design has released a brace of freeware 3D-modelling products for the Mac.
Using Apple's Open GL extensions, ClayScape 3D and ClayScape 3D4Kids allow real-time interactive sculpting of "virtual clay". The software is designed for G3 Macs equipped with 3D accelerator-cards.
Basic system requirements are a Power Macintosh, Mac OS 7.6 or later, and a minimum of 10MB free RAM. ClayScape 3D supports Wacom tablets.
ClayScape 3D also requires Apple OpenGL libraries, which must be installed in the Extensions folder.