This package provides algorithms for working with polycyclic groups in GAP. The features of this package include: - creating a polycyclic group from a polycyclic presentation - arithmetic in a polycyclic group - computation with subgroups and factor groups of a polycyclic group - computation of standard subgroup series such as the derived series, the lower central series - computation of the first and second cohomology - computation of group extensions - computation of normalizers and centralizers - solutions to the conjugacy problems for elements and subgroups - computation of Torsion and various finite subgroups - computation of various subgroups of finite index - computation of the Schur multiplicator, the non-abelian exterior square and the non-abelian tensor square