Since its inception in the 1980s, Artificial Life is an interdisciplinary field of science focused on abstracting the essential features and dynamics of living systems in order to create artificial life-like and living systems. In 1995, the first German Workshop on Artificial Life (GWAL) was organized by young researchers who were interested in this newly emerging science and wanted to discuss their projects and results in an open, informal atmosphere. The 7th GWAL, which was held in Jena 2006, continued the successful series of these workshops. It was attended by young scientists not only from Germany but also from several other European countries and from Japan. The contributions in this book cover many different topics of Artificial Life, such as information and category theoretical models of living systems, the computational relevance of the physical substrate of life, the logic of genetic regulatory networks, and new approaches to artificial chemistries.