It is not GRASS, but the MAP II package is fairly nice and does run under
the normal Mac OS. It is available from John Wiley (documentation and
academic site license) for about $120.
--
Duane F. Marble E-mail: dmarble@magnus.acs.ohio-state.edu
Department of Geography
The Ohio State University Telephone: (614) 292-2250
Columbus, Ohio 43210 Fax: (614) 292-6213