GAP package Cubefree: Constructing the Groups of a Given Cubefree Order. The Cubefree package contains methods to construct up to isomorphism the groups of a given (reasonable) cubefree order. The main function ConstructAllCFGroups(n) constructs all groups of a given cubefree order n. The function NumberCFGroups(n) counts all groups of a cubefree order n. Furthermore, IrreducibleSubgroupsOfGL(2,q) constructs the irreducible subgroups of GL(2,q), q=p^r, p>=5 prime, up to conjugacy and RewriteAbsolutelyIrreducibleMatrixGroup(G) rewrites the absolutely irreducible matrix group G (over a finite field) over a minimal subfield.