It is quite easy to learn and includes a help file. Some of these features are custom palettes, overworld editing, custom Map16 pages, custom graphics, entrance/exit modifying, support for custom blocks, sprites and (recently) custom music.
It has many features and is an extremely advanced editor.
The interface runs on Microsoft Windows and allows people to create custom graphics and edit levels and the world map. Lunar Magic is a level editor created by FuSoYa for Super Mario World.