Stef, The class can be more flexible than what is in Pharo, and FWIW, is not built into the system. Since it does not need to be built-in, that's a plus in my thinking. Not much of a difference, I must admit. Bill Wilhelm K. Schwab, Ph.D. University of Florida Department of Anesthesiology PO Box 100254 Gainesville, FL 32610-0254 Email: bschwab@anest.ufl.edu Tel: (352) 273-6785 FAX: (352) 392-7029