Large amounts of 'raw' genomic sequence data already exist and continue to grow exponentially. Many tools are available for automated analysis of these data by comparison to known sequences or by pattern recognition. One of the hardest problems is how to present the sequence data and its derived annotation in an intuitive way. We present here a workbench for analysis of large-scale genomic sequence data, with strong emphasis on the production of enriched graphical representation of the analysed data. The GESTALT Workbench can execute a variety of external analysis programmes (e.g.