This Festschrift volume, published in honor of Egon B?rger, contains 14 papers from a Dagstuhl Seminar, which was organized as a "Festkolloquium" on the occasion of his 60th birthday in May 2006. Focusing on applied formal methods, the volume covers a wide range of applied research, spanning from theoretical and methodological foundations to practical applications of Abstract State Machines, B, and beyond, emphasizing universal methods and tools that, regardless of their applicational orientation, are still committed to the ideal of mathematical rigor. In particular, the papers address the following central topics: methodological foundations of requirements specification and verification, characterization of specification languages and their logical foundations, advanced tool environments and systematic integration of tools, machine assisted validation and verification, distributed algorithms and concurrent protocols, novel applications in public safety, security and privacy, industrial case studies and experience reports, and the role of formal methods in computer science education.