POLICY ON COMMERCIAL DISTRIBUTION OF CLUSTAL W Clustal W is freely available to the user community. However, Clustal W is increasingly being distributed as part of commercial sequence analysis packages. To help us safeguard future maintenance and development, commercial distributors of Clustal W must take out a NON-EXCLUSIVE LICENCE. Anyone wishing to commercially distribute version 1.8 of Clustal W should contact the authors unless they have previously taken out a licence. gibson@embl-heidelberg.de thompson@embl-heidelberg.de d.higgins@ucc.ie