In the literature, several terms are used synonymously to name the topic of this book: chem-, chemi-, or chemo-informatics. A widely recognized de- nition of this discipline is the one by Frank Brown from 1998 (1) who defined chemoinformatics as the combination of all the information resources that a scientist needs to optimize the properties of a ligand to become a drug. In Brown s definition, two aspects play a fundamentally important role: de- sion support by computational means and drug discovery, which distinguishes it from the term chemical informatics that was introduced at least ten...