BRIG can display circular comparisons between a large number of genomes, with a focus on handling genome assembly data. * Images show similarity between a central reference sequence and other sequences as concentric rings. * BRIG will perform all BLAST comparisons and file parsing automatically via a simple GUI. * Contig boundaries and read coverage can be displayed for draft genomes; customized graphs and annotations can be displayed. * Using a user-defined set of genes as input, BRIG can display gene presence, absence, truncation or sequence variation in a set of complete genomes, draft genomes or even raw, unassembled sequence data. * BRIG also accepts SAM-formatted read-mapping files enabling genomic regions present in unassembled sequence data from multiple samples to be compared simultaneously