Summary: Correspondence analysis of codon usage data is a widely used
method in sequence analysis, but the variability in amino acid
composition between proteins is a confounding factor when one wants to
analyse synonymous codon usage variability. A simple and natural way to
cope with this problem is to use within-group correspondence analysis.
There is, however, no user-friendly implementation of this method
available for genomic studies. Our motivation was to provide to the
community a Web facility to easily study synonymous codon usage on a
subset of data available in public genomic databases.