This plot is a modification of the Kerry Rodden's Sequences sunburst which has been modified to accomidate a hierarchy instead of patterns of sequences (e.g., web click-through rates). It has also been linked to the Data Tables, a jQuery JavaScript library to display create a paginated table of the datapoints found in each category.
The data being displayed is a classification of 507 publicly-available environmental metagenomes contained in the Integrated Microbial Genomes System (IMG/M) and MG-RAST genomeic annotation servers and data repositories. The data are divided into many categories, but start at Environmental (Aquatic, Terrestrial, Air), Host-associated (Human, Insect Gut), Engineered, and Viruses.
The colors are somewhat complicated as they are mix and match of Cynthia Brewer's ColorBrewer pallets; trying to keep