Activision Blizzard develops and publishes software titles such as World of Warcraft, StarCraft, Diablo, Heroes of the Storm, Hearthstone, and Overwatch. Blizzard offers its online gaming service that enables millions of players around the world to communally play its games. The games are sold through retailers and online download. The company has also expanded its popular game franchises into related products such as action figures, board games, graphic novels, and comic books