The SRIM code is used for calculating physical quantities related to ion-beam modification of materials. This paper presents supporting routines for the SRIM code, that improve its validity, precision, and ease of use of, make a link to the formalisms used in ion-optics and generally broaden its application potential. Several routines have been merged into a single software package S 3 M – SRIM Supporting Software Modules. S 3 M enables the user to calculate beams traversing thin targets, to run SRIM with finite-emittance beams and to simulate beam-transport with scattering and collimation. It has been successfully tested and used for the simulation of beam-transport channels and ion-implantation.