This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2018) Abstract Aside from numerical algorithms and problem setup, large-scale physics simulations on distributed-memory supercomputers require more basic utilitarian functionality, such as physical units and constants; display to the screen or standard output device; message passing; I/O to disk; and runtime parameter management and usage statistics. Here we describe and make available Fortran 2003 classes furnishing extensible object-oriented implementations of this sort of rudimentary functionality, along... Title of program: GenASiS Catalogue Id: AEXE_v1_0 Nature of problem By way of illustrating GenASiS Basics functionality, solve example fluid dynamics and molecular dynamics problems. Versions of this program held in the CPC repository in Mendeley Data AEXE_v1_0; GenASiS; 10.1016/j.cpc.2015.06.001