Invited Tutorial -- Research Issues in the Renovation of Legacy Systems -- Invited Paper -- Continuous Engineering of Information and Communication Infrastructures -- Contributed Papers -- A Formal Framework with Late Binding -- Yet Another Real-Time Specification for the Steam Boiler: Local Clocks to Statically Measure Systems Performance -- Executable Tile Specifications for Process Calculi -- JTN: A Java-Targeted Graphic Formal Notation for Reactive and Concurrent Systems -- Conservative Extension in Positive/Negative Conditional Term Rewriting with Applications to Software Renovation Factories -- Dynamic Systems with Implicit State -- Rigorous Development in UML -- Using Explicit State to Describe Architectures -- On the Evolution of Reactive Components -- Verification of Definite Iteration over Hierarchical Data Structures -- Owicki/Gries in Isabelle/HOL -- Semantic-Driven Performance Evaluation -- Implementing Hierarchical Graph-Structures -- Demos -- A Tool Suite for Multi-Paradigm Specification -- TAS and IsaWin: Tools for Transformational Program Development and Theorem Proving.

ETAPS’99 is the second instance of the European Joint Conferences on Theory and Practice of Software. ETAPS is an annual federated conference that was established in 1998 by combining a number of existing and new conferences. This year it comprises ?ve conferences (FOSSACS, FASE, ESOP, CC, TACAS), four satellite workshops (CMCS, AS, WAGA, CoFI), seven invited lectures, two invited tutorials, and six contributed tutorials. The events that comprise ETAPS address various aspects of the system - velopment process, including speci?cation, design, implementation, analysis and improvement. The languages, methodologies and tools which support these - tivities are all well within its scope. Di?erent blends of theory and practice are represented, with an inclination towards theory with a practical motivation on one hand and soundly-based practice on the other. Many of the issues involved in software design apply to systems in general, including hardware systems, and the emphasis on software is not intended to be exclusive.