Remere's Map Editor (RME) is a map editor designed to work in conjunction with various OpenTibia tools. It's most innovative feature is auto-bordering, which was not introduced to OpenTibia before this map editor was published.
It is interesting that Remere's Map Editor gained fame and popularity even before its official release. It was leaked without author's consent, and it gained popularity extremely rapidly. About two months later the official version of the map editor was finally released.