SCOL : The Structural Classification of Ligands http://www.bioinformatics.org/scol/ The objective of the SCOL project is to produce a global hierarchical clustering of all the available small molecules and protein ligands using measures of structural, chemical and biological 'similarity' between molecules. At a broad level, this hierarchical classification should reflect biological and chemical intuitions about the major classes of molecule and their broad physical and chemical characteristics. At a more detailed level of classification, structurally and chemically similar molecules should be grouped together. This classification system should prove useful for diverse studies, from the gross assessment of metabolic evolution to ligand binding studies. The ultimate aim is to assist in the process of drug discovery and lead compound identification. A distinct sub project of SCOL is the derivation of a set of 'representative' or 'non-redundant' compounds for input into more detailed structural and functional studies.