Extell Development is a New York City-based real estate development company founded by former diamond dealer Gary Barnett in the early 1990s. The company was known as Intell Management and Investment until 2005. Its projects have included the 1,000-foot One57; the W Hotel in Times Square, which opened in 2002; 45 Walker Street, an office-to-loft-condominium conversion in Tribeca; and the International Gem Tower in the Diamond District. It is developing a supertall mixed-use condominium along Billionaires' Row at 217 West 57th Street in Midtown called Central Park Tower. The first few floors of the tower will house Nordstrom, an upscale department store.