RCWA is a package for GAP 4. It provides implementations of algorithms and methods for computing in certain infinite permutation groups acting on the set of integers. This package can be used to investigate the following types of groups and many more: • Finite groups, and certain divisible torsion groups which they embed into. • Free groups of finite rank. • Free products of finitely many finite groups. • Direct products of the above groups. • Wreath products of the above groups with finite groups and with (Z,+). • Subgroups of any such groups. With the help of this package, the author has found a countable simple group which is generated by involutions interchanging disjoint residue classes of Z and which all the above groups embed into – see [Koh10].

This software is also referenced in ORMS.