Transavision Ltd., doing business as GSC Game World, is a Ukrainian video game developer based in Kiev, Ukraine. Founded in 1995 by Sergey Grigorovich, it is best known for the Cossacks and S.T.A.L.K.E.R. series of games. Their first game was the 2000 Cossacks European Wars, which directly led to their breakthrough. In 2004, GSC Game World opened their publishing arm, GSC World Publishing, which would publish and distribute their titles in the Commonwealth of Independent States. Their next successful series, S.T.A.L.K.E.R., started with S.T.A.L.K.E.R. Shadow of Chernobyl, and was followed up with two sequels in 2008 and 2009, respectively.