Welcome to the fourth issue of the ACM Computers in Entertainment online magazine! In this exciting new issue, we publish six interesting papers on entertainment technologies from authors around the world including Greece, Malaysia, Portugal, UK, and USA. We also feature video interviews with our distinguished advisory board members Prof. Dr. Cynthia Breazeal, MIT Media Lab's Robotic Life Group, and MP3 inventor Prof. Dr. Karlheinz Brandenburg, the Fraunhofer Institute.