It will not be our purpose in this chapter to give an introduction to the field of abstract data types proper. There are many such introductions - see the references in the bibliography. We intend rather to provide a beginner's guide to the 870 papers cited there. For experts, the 1 i st of those programmi ng languages and systems which appear in the titles should prove useful. We shall not recommend one single paper as a starting point but mention several papers which cover various aspects of the theory. Historically, the papers of [PARNAS 70] and [HOARE 72] are generally regarded as the...