Wikipedia

Wikipedia is a free, collaborative online encyclopedia launched in 2001 that coordinates contributions from millions of editors without central planning. The platform uses quorum-like mechanisms where article quality emerges from watcher density - editors add articles to watchlists, and high-watch articles self-maintain through distributed editing while low-watch articles deteriorate.

Wikipedia exemplifies density-dependent quality coordination: the watchlist system functions as a quorum signal where collective action (quality maintenance) is triggered when enough individuals signal their presence. The Featured Article process requires consensus quorum - typically 4-5+ support votes with no unresolved objections - before articles achieve highest-quality recognition.