Programs and program systems in wide use

Macromolecular programs and program systems in wide use are described. The chapter covers PHASES; DM/DMMULTI, software for phase improvement by density modification; the structure-determination language of the Crystallography & NMR System; the TNT refinement package; the ARP/wARP suite for automated construction and refinement of protein models; validation of protein-structure coordinates with PROCHECK; MolScript; MAGE, PROBE and kinemages; XDS; and macromolecular applications of SHELX.