Supports sparse and dense matrix representations. BIOM is a format developed to be a general-use format for representing biological sample by observation contingency tables. This project is designed for general use in broad areas of comparative -omics. This format may be used to represent a set of genomes: the observations in this case again might correspond to SEED subsystems, and the counts would correspond to the number of times where each subsystem is observed in each genome. The BIOM package provides a command line interface and Python API for working with BIOM files.