WMS Gaming is one of two subsidiaries of WMS Industries, whose roots date back to the 1943 founding of Williams Manufacturing Company. Williams produced a line of pinball machines and video arcade games, spinning the latter business into a separate company, Midway Games. In 1991, operating under the name Williams Gaming, the company introduced video lottery terminals. Williams subsequently entered the casino gaming business with a video poker game, followed by a line of slot machines. Williams Gaming became WMS Gaming in 1999 and has since focused exclusively on the manufacture, sale, leasing, licensing and management of gaming machines.