StarCraft II: Wings of Liberty is a military science fiction real-time strategy video game developed and released by Blizzard Entertainment for Microsoft Windows and Mac OS X. A sequel to the award-winning 1998 video game StarCraft and its expansion set Brood War, the game was released worldwide on July 27, 2010. The campaign storyline of StarCraft II takes place four years after StarCraft: Brood War, and features the return of Zeratul, Arcturus Mengsk, Artanis, Sarah Kerrigan, and Jim Raynor. It also features new characters such as Rory Swann and Tychus Findlay. In StarCraft II, players revisit familiar worlds, like Char, Mar Sara, and Tarsonis, as well as new locations, such as the jungle planet Bel'Shir and New Folsom. The Xel'Naga, an ancient space-faring race responsible for creating the Protoss and the Zerg, also play a major role in the story.