This Special Part of the ANZIAM Journal (Electronic Supplement) contains the refereed papers from the eleventh Biennial Computational Techniques and Applications Conference (CTAC2003) held at ICIAM, Sydney 2003. The editors acknowledges the advice and assistance provided by Jerard Barry with the refereeing process. The CTAC series of conferences is held under the auspices of the Computational Mathematics Group of the Australian and New Zealand Industrial and Applied Mathematics (ANZIAM) division of the Australian Mathematics Society. They provide a forum for scientists, engineers, and mathematicians interested in the development of computational techniques and their application to problems of practical importance. Previous conferences in th...