The Semantic Web offers powerful capabilities for knowledge formalization, integration, and
query. However, semantic web applications are still limited in scope and impact. There are some
remarkable applications in the Health Care and Life Science areas, but semantic web
technologies have not reached yet a widespread popularity. One of the obstacles is that the
resulting applications are often sophisticated, difficult to use, and not intuitive. We need more
user-friendly and usable applications, providing rich user experiences. By combining the
strengths of Semantic Web and Web 2.0, these kinds of applications can become a reality and
speed up the web (r)evolution.