OpenStreetMap is celebrating its 20th anniversary today. It was originally created in response to restrictive Ordnance Survey licensing in the U.K., in a context that seems unrecognizable today. Founder Steve Coast writes about the anniversary (mirror link). “Allowing volunteers to edit a map in 2004 was simply anathema and bordering on unthinkable. Map data was supposed to be controlled, authorized and carefully managed by a priesthood of managers.”