US Federal Bureau of Investigation (FBI), and other US government agencies, licensed the Unreal Engine from Epic. Unreal is one of the most popular cross-platform game engines in the industry, and United States, through various agencies will use the engines in "serious games", games designed to simulate situations such as crime scenes, encounters, casualty treatment, for the agents to learn to deal with. While the full financial details of these deals were not disclosed, the deal with FBI Intelligence Advanced Research Projects Activity (IARPA) earned Epic around US $10 million.