As the title suggests, which RPG's do not involve the position of a gamemaster, of a person who presents the others with the world and events, but instead depend on all participants narrating (or deciding how narration will resume between them) for each session?
Answers should not include games where players narrate as well but there is still a GM (example - Burning Wheel, Mouse Guard, etc. where there is a Players' Turn) but should instead include games where the players present each other (and/or themselves) with obstacles they have to overcome, without the involvement of a person deciding everything.