It was first prototyped by two users[1][2] during the Chicago Hack weekend on the 26th-28th April 2013. This was conceived to be an enhancement to the OSM history tab with other notable users of the community working[3][4] on coming up with a solution for a history tab that shows all objects status visualized within a changeset on the web.
A hacked version of this prototype has been created with aims into saving bandwith and rendering time and/or allows lower zoom levels. It will show changes made in the last 24h, 3 days, 7 days or 30 days.
As of July 2022 another updated version has been created, that offers added functionality, i.e. a tag comparison table and a vandalism checker.