None of the map info or location info is exposed via the Lua API so map plugins are seriously limited in capabilities, add to that the limitations on real-time data saving and loading and maps become even more limited. That said, there are two map plugins, MoorMap and TerrainMap which stretch the limits of the API about as far as it can go.
MoorMap is a fully annotated version of the in-game parchment maps with several enhancements such as custom user annotations, overlays, etc. that are not available from the built-in map. MoorMap is resizable / repositionable and translated for EN/DE/FR clients. MoorMap is also integrated with LunarWater's Waypoint plugin. MoorMap includes Whiteberry's "Berry's Deed Data" as overlays - unfortunately Whiteberry has since stopped creating the deed guides.
TerrainMap is a "Google" style map using the in-game compass (radar) terrain backgrounds. Due to a bizarre development decision on the part of Turbine, TerrainMap is divided in to three maps, one for each region as the regions use different coordinate origins and overlap. TerrainMap does not (currently) support full annotations due to the inability to dynamically load/unload annotations while scrolling (loading all of the annotations, even for a single region, would negatively impact the client performance). However, TerrainMap does allow access to the MoorMap data files for a global search feature that allows users to temporarily place an annotation on the terrain. I am experimenting with a limited version of dynamically loaded annotations which might respond well enough to implement the basic annotations (no user entered data) but that is still subject to a LOT of testing and will definitely not make it in time for the U18 update. TerrainMap's User Interface is not translated for DE/FR clients but that is still on the ToDo list and may eventually be implemented.