DNA Computing : 9th International Workshop on DNA Based Computers DNA9 Madison WI USA June 1 3 2003. Revised Papers This book constitutes the thoroughly refereed post proceedings of the 9th International Workshop on DNA Based Computers DNA9 held in Madison Wisconsin USA in June 2003. The 22 revised full papers presented were carefully selected during two rounds of reviewing and improvement from initially 60 submissions. The papers are organized in topical sections on new experiments and tools theory computer simulation and sequence design self assembly and autonomous molecular computation experimental solutions and new computing models