Artificial Life is a still growing interdisciplinary research field integrating a variety of different theoretical foundations, methodological positions, applications and disciplines. The main focus of this science is to abstract and to synthesize the essential features and dynamics of living systems in order to create artificial, life-like systems. On a regular basis and from 1995 on the German Workshop on Artificial Life is organized. Like previous workshops the 6th German Workshop on Artificial Life in 2004 provided the opportunity for scientists from a broad spectrum of research areas to get in touch with their colleagues from different disciplines, to learn from one another about questions of mutual interest and to have a forum for scientists who would like to get into contact with the Artificial Life community. Contributions to the GWAL 2004 result from research efforts from (and may be of interest to) biology, physics, information and computer science, chemistry, mathematics, psychology, sociology, philosophy, robotics, socionics and much more.