Dota 2 is an Action RTS game, developed by Valve Corporation. The title was formally announced on October 13, 2010; and was released as a Free to Play game on July 9th, 2013 for Windows, and July 18th, 2013 for Mac OS and Linux. It is the successor to the very popular Warcraft 3 mod, Defense of the Ancients, which was based on the Aeon of Strife map for StarCraft.