This volume comprises the invited surveys and revised versions of the submitted papers selected for presentation at the 10th Workshop on Specification of Abstract Data Types, held jointly with the 4th COMPASS Workshop in S. Margherita, Italy in June 1994.The volume gives a comprehensive state-of-the-art report of the research activities: besides classical algebraic techniques, other relevant topics are investigated, such as formalisms based on general logics and category theory, type systems for specification languages and new structures for modelling dynamic systems. In addition to four surveys by prominent leaders in the area and 23 papers presenting original research, the book contains an annotated bibliography covering all contributions to the ten editions of the workshop.