The volume contains the 23 papers selected for presentation at the ESOP '88 Conference, Nancy 1988. The theme of the ESOP conferences is the design, specification and implementation of programming languages and systems. Particular emphasis is placed on work in which an implemented system embodies an important concept or formal model of programming in such a way that its usefulness is demonstrated. Among the five sections of the volume, the one on language implementation contains the most papers. Here a rather wide spectrum of aspects, ranging from language implementation problems on parallel architectures and optimization of functional programs to new concepts for programming environments is covered. Another large section consists of papers in the area of algebraic specification and type concepts. The papers in this section are devoted to issues such as polymorphism, subtypes and notions of implementation and reuse for algebraic specifications. Two further sections are devoted to new language concepts and novel approaches to program development and verification.