Computing with Abelian sections of finitely presented groups

Let G be a finitely presented group. This paper describes the theory and pr actice of a method for obtaining information about the finite and abelian-b y-finite quotients of G, which often allows computation about larger quotie nts of the group than has been possible by more traditional methods. The pa per also describes the authors' software package quotpic, which provides a user-friendly implementation of the algorithms involved in this method, as part of a complete range of facilities for computing various types of quoti ents of finitely presented groups. (C) 1999 Academic Press.