PermLib is a C++ library for permutation computations. Currently it supports set
stabilizer and in-orbit computations, based on bases and strong generating sets
(BSGS). Additionally, it computes automorphisms of symmetric matrices and finds
the lexicographically smallest set in an orbit of sets. It also features a very
basic recognition of permutation group types.

WWW: http://www.math.uni-rostock.de/~rehn/software/permlib.html