Red Hat remains the leader in U.S. retail Linux sales, according to a new report from PC Data, but rival Corel is quickly gaining ground. The research firm reported that Red Hat accounted for 40.4 percent of retail Linux sales in February 2000, down from 58.5 percent in November 1999. Macmillan was second with 19.6 percent, down slightly from 21.5 percentin November. Corel surged into third place with 19.3 market share, way up from 2.3 percent in November. S.U.S.E., TurboLinux and Caldera rounded out the top six.