GrpConst is a GAP 4 package for constructing all groups of a given finite order (up to isomorphism). FrattiniExtensionMethod constructs all soluble groups of a given order. CyclicSplitExtensionMethod constructs all (necessarily soluble) groups whose given orders are of the form pn .q for different primes p and q and which have at least one normal Sylow subgroup. UpwardsExtensions takes as its input a permutation group G and positive integer s and returns a list of permutation groups, one for each extension of G by a soluble group of order a divisor of s. The programs in this package have been used to construct a large part of the Small Groups library.