MoSS is mainly a program to find frequent molecular substructures and discriminative fragments in a database of molecule descriptions. It can be used in the context of drug discovery and synthesis prediction for the purpose of analyzing the outcome of screening tests. Given a database of graphs, MoSS finds all (closed) frequent substructures, that is, all substructures that appear with a user-specified minimum frequency in the database (and do not have super-structures that occur with the same frequency).

MoSS has been included in CheS-Mapper