Mark Overmars is a full professor in Computer Science at Utrecht University in the Netherlands. Here he heads the center for Advanced Gaming and Simulation. One of his research domains is computer games. He is one of the founders of the Utrecht Platform for Game Education and Research and teaches courses on computer game design at Utrecht University. Mark is the author of many software packages. In particular, he is the author of the Game Maker software package which will be used as development tool in this book.