Published with Gap 4: 
 Aclib  Almost Crystallographic Groups. With K. Dekimpe.
GAP page
 Alnuth  ALgebraic NUmber THeory interface.
With B. Assmann and A. Distler.
GAP page
 AutPGrp  Automorphisms finite pgroups. With E. O'Brien.
GAP page
 CrystGAP  Crystallographic groups.
With F. Gaehler and W. Nickel.
GAP page
 Format  Formation theoretic subgroups.
With C.R.B. Wright.
GAP page
 GrpConst  Computing the groups of a given order.
With H.U. Besche.
GAP page
 LiePRing  The Lie rings of order at most p^7.
With M. VaughanLee.
GAP page and some notes
 ModIsom  Automorphisms and Isomorphisms for nilpotent
associative algebras.
GAP page
 Polycyclic  Computing with infinite polycyclic groups.
With M. Horn and W. Nickel
GAP page
 SglPPow  The groups of order 3^8 and p^7.
With M. VaughanLee.
GAP page
 Small Groups  A large library of small groups.
With H.U. Besche and E. O'Brien.
Web page and
GAP page



Archives of code for Gap 4: 
 AutVAbel  Computing the automorphism group of a
polycyclic space group.
tar.gz archive
 Coclass  Coclass methods for pgroups.
tar.gz archive.
 EnumPGrp  Enumerating pgroups
tar.gz archive and
Readme file
 FinLie  Lie algebras over finite fields.
With T. Moede.
tar.gz archive
 GalGrp  Galois groups of certain maximal 2extensions of Q.
Readme and
tar.gz archive
 TGroupIsom  Code corresponding to 'The isomorphism problem for torsion free nilpotent groups of Hirsch length at most 5'.
With A.K. Engel.
README file and
gapcode


