A level editor for the DS game New Super Mario Bros, originally made by Treeki and now maintained by Dirbaio. Aka NSMBe. Features:

• Complete editing: Graphics are accurate. You can modify objects, sprites, entrances/exits, views and paths - so practically anything in the level can be edited!
• Mini-map: Click the View Mini-map button to show a mini-map of the level you’re currently viewing. You can also click and drag to scroll the view.
• Integrated file browser: Browse, extract and replace files in the ROM easily without a separate program, for more advanced hacking. Export Level: A level can be exported to a file, and later imported back in (either to the same slot, or a different slot). Multiple Windows: You can open and edit as many levels as you like in the same editor.
• Sprite List and Data Editing: Almost every sprite in the game is now identified and selectable in a list! Invalid sprites which won’t work in a level are highlighted in red, and they can be made usable by changing the sprite set used. Note that some need specific sprite data to set up correctly. Some sprites have their data selectable using simple options.
• Tile-set and Graphics Editing: You can create new tile-sets with completely new objects and tiles. Two options are available for editing the graphics: a simple integrated graphics editor, or PNG import/export.
• Level Hex Editor: For stuff not supported by the editor, edit individual blocks in a level file without having to constantly import/export files.
• More stuff, recently