In 1998, the company received a DARPA research contract which led to the development of the PackBot.[5] In September 2002, iRobot unveiled its home robots flagship, the Roomba, which sold a million units by 2004.[6] iRobot began being traded on the NASDAQ in November 2005, under ticker symbol IRBT.[7] On September 17, 2012, iRobot announced that it had acquired Evolution Robotics, manufacturer of automated floor mopper Mint.[8]