Since ASINEX's foundation in 1994 we have gained more than 15 years of experience in the design, synthesis and supply of small molecule compound libraries. ASINEX started off by collecting compounds from external sources and has gradually increased its level of library design and medicinal chemistry expertise. Since 2004, ASINEX has been focusing on the design of high value compound libraries that have exceptionally novel scaffolds and incorporate privileged features of known leads and drugs. ASINEX has gone far beyond merely paying attention to the rule of 5, attention has been paid to structural features that can cause problems later during the stage of lead optimization and beyond. Since 2008 ASINEX has added to its expertise in designing novel lead-like scaffolds, by also incorporating natural product privileged features into synthetic scaffolds. Rigidity, 3D-shape and good solubility are important drug-like features that require a high degree of synthetic expertise and design know-how, this is the area that ASINEX is currently exploring.