This review explores the UK CropNet site. The project is aimed at aiding the comparative mapping of cereal and other crop genomes. The site provides software tools for use by those working on genome mapping, and access to an array of databases that will be of interest to all members of the plant genomics research community, using several ACeDB interfaces. All screen views from the website are reproduced with the kind permission of Dr Sean May, Director, Nottingham Arabidopsis Stock Centre (NASC).