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Official Description

NotTiled is a simple .tmx tile map editor for game developers. It is based on Tiled Map Editor (https://www.mapeditor.org/) by Thorbjørn Lindeijer. Don't expect this to be as good as Tiled tho....

Sample maps & tilesets included (credit to their own respective creators).

Features currently supported:
- Orientation: Orthogonal, Isometric (partly)
- Map size tested up to 3000x3000 tiles
- Map format: xml, csv, base 64, base 64 zlib compressed, base 64 gzip compressed
- Render order: right-down, left-down, right-up, left-up
- Multiple tileset (also supports .tsx file)
- Multiple tile layers
- Multiple object layers
- Animations
- Custom properties for map, tiles, and objects
- Editing tools: Pencil tool, Stamp, Flood fill, and Terrain tool
- Tile rotation and flip
- Undo and redo (at present only for tile mapping)
- Objects supported: Rectangle, ellipse, point, polygon, polyline, text (partially), and image
- Copy paste objects

Still not implemented yet:
- Staggerred and Hex map
- Wangset
- Template
- Object on isometric map
- Auto map
- Export to other formats

Please contact me if you found bugs/errors. My goal is to make NotTiled bug free for everyone.

Tutorials:
https://www.youtube.com/watch?v=WoWju39Tae8&list=PLaZhehDwQZIKlNPsMKqR3YRYxvdWctWt9