Ben said >>> Which one? <<< The one people seem to use is called pocket mine. (https://www.pocketmine.net). There may be others.
>>> I was thinking of the standard PC version since I understood the PE version was not so amenable to mods. Actually my kids have been playing PE edition on iPads, and I bought them second hand laptops to run the PC edition to do modding. Still discovering how it all works. <<< The PE (iPad etc) version seems to be catching up in terms of features, and it does allow some level of mods. However, I agree that the full PC version is probably the better target. I wonder if there are any docs that list the Api we need to support.