gap:

This directory contains the gap code to compute with infinite
polycyclic groups. It is splitted in various subdirectories:

matrix     --  basic stuff for rational modules and related
basic      --  basic stuff for pcp groups, collector etc.
cohom      --  cohomology for pcp groups, complements and extensions
action     --  actions of polycyclic groups and orbit-stabilizer methods
pcpgrp     --  higher level functions for pcp groups
matrep     --  computing a matrix representation for a pcp group
exam       --  examples of pcp groups

Each directory has its own README file containing more information
about the various files containing the code.