1. (a) BIOGRAF, BioDesign, Inc., Pasadena, CA, USA
2. (b) CHARM, HYDRA, QUANTA, Polygen Corporation, 200 Fifth Avenue, Waltham, MA 02254, USA
3. (c) Chem-X, Chemical Design Ltd., 7 West Way, Oxford, UK
4. (d) DISCOVER, INSIGHT, Biosym, 10065 Barnes Canyon Road, San Diego, CA 92121, USA
5. (e) FRODO, Jones, A. Max-Planck-Institut fur Biochemie, Martinsried, FRG