League of Legends (LoL) is a multiplayer online battle arena video game developed and published by Riot Games for Microsoft Windows and Mac OS X, inspired by the popular Defense of the Ancients map for Warcraft III. It is a free-to-play game, supported by micro-transactions. It was first announced on October 7, 2008, and released on October 27, 2009.League of Legends was generally well received at release, and has grown in popularity in the years since. Riot Games claims that League of Legends averages over 12 million players worldwide per day, with peak concurrent global players over 5 million players.