This Festschrift is in honor of Egon Börger on the occasion of his 80th birthday. It reflects his impact as a scientist, author, mentor, and community organizer. A pioneer in the fields of logic and computer science, Egon Börger's research interests are unusual in scope, from programming languages to hardware architectures, software architectures, control systems, workflow and interaction patterns, business processes, web applications, and concurrent systems.Prof. Börger has collaborated with a wide range of scientists and practitioners, their interests and successes are reflected in the papers contributed to this volume.