This book grew out of discussions with Dr. Rainer Moufang, my long-time friend from the Max Planck Institute for German and International Intellectual Property (The institute has been renamed as the Max Planck Institute for Intellectual Property, Competition and Tax Law). On a cold, quiet afternoon in Munich in 2006, we sat in his office discussing the need for a comprehensive review of fundamental and contemporary patent issues as they relate to the protection of both traditional and new technologies. We envisioned a book that would appeal to both academics and practitioners, and we selected experts from three major patent jurisdictions – the United States, Europe and Japan – who could write on each topic. Although we granted these authors complete freedom with regard to writing style, we strongly encouraged them to analyze their topics from the comparative law perspective.