Professionalism: Ideas and Cases in Engineering Ethics is a wikibook written by about 200 students from the University of Virginia's School of Engineering and Applied Science. The book was begun in the spring semester, 2011; the authors have been students in STS 4600: "The Engineer, Ethics, and Professional Responsibility." This class is the second in a two-semester sequence for fourth-year engineering students. In the fall semesters of 2010 and 2011, students were enrolled in STS 4500: "Case Studies in Technology and Society." This class produced Lentis, a guidebook to the realm where technological phenomena and social phenomena intersect.