Description Data Domain keeps datasets down to reasonable sizes. The company develops de-duplication appliances for data backup systems and other storage applications. Based on proprietary compression technology, its systems identify redundant files to reduce the amount of data that has to be stored. Its customers include enterprises in the defense, entertainment, finance, health care, legal, media, and retail sectors. The company has served TiVo, the Philadelphia Phillies, the City of Houston, and Xcel Energy. Data Domain also generates revenue from maintenance and support services. In 2009 Data Domain was acquired by data storage systems leader EMC.