The aim of the series of IPCAT workshops is to bring together a multidisciplinary core of scientists who are working in the general area of modeling information processing in biosystems. A general theme is the nature of biological information and the ways in which it is processed in biological and artificial cells and tissues. The key motivation is to provide a common ground for dialogue and interaction, without emphasis on any particular research constituency, or way of modeling, or single issue in the relationship between biology and information. IPCAT2003 will highlight recent research and seek to further the dialogue, exchange of ideas, and development of interactive viewpoints between biologists, physicists, computer scientists, technologists and mathematicians that have been progressively expanded throughout the IPCAT series of meetings (since 1995).