He's also running AtlasLoot, which has tons more info than Cartographer provides. Though AtlasLoot runs just as well standalone (has a FuBar plugin even). And Atlas shows outdoor bosses, Cart doesn't. Not that you can really get lost there... ;) And Atlas doesn't put coordinates on the world map, unless it was recently added.
Anyway, my money's on NavigatorFu. Especially since the description is "A lightweight and minimalistic coordinate mod."