Domark Software was a video games software house based in the United Kingdom. The name was derived from the given names of its founders, Dominic Wheatley and Mark Strachan. Domark developed and published many games for home computers during the 1980s. The company's first release was the 1984 title Eureka!, an adventure game created by Ian Livingstone, which was notable for offering a £25,000 prize to the first person to completely solve the game. In 1995, Domark merged with Eidos Technologies, Simis and Big Red Games to form the Eidos Interactive group. Eidos Interactive later acquired U.S. Gold which included Core Design.