The fledgling field of DNA computers began in 1994 when Leonard Adleman surprised the scientific community by using DNA molecules, protein enzymes, and chemicals to solve an instance of a hard computational problem. This volume presents results from the second annual meeting on DNA computers held at Princeton only one and one-half years after Adleman's discovery. By drawing on the analogy between DNA computing and cutting-edge fields of biology (such as directed evolution), this volume highlights some of the exciting progress in the field and builds a strong foundation for the theory of molecular computation.