The official free-to-play sequel to the Warcraft III custom scenario that originally popularized the Multiplayer Online Battle Arena sub-genre.
AdmiralBulldog is a very famous former Dota 2 pro player, who used to be at the very top of the scene. He became a full-time streamer years ago and has since then acquired a large fan base. He's been playing various games on his stream, but always ends up coming back to Dota for more high-level games.