Tiled

Tiled is a general purpose tile map editor created by Thorbjørn Lindeijer, released under the GNU General Public License. It allows you to create orthographic, isometric and hexagonal maps using 2D images. Tiled is equipped with a whole range of tools that allows for an efficient world creation workflow for almost any 2D game.

It uses an XML based file formats for tile maps (*.tmx) and tilesets (*.tsx) for use in-game. TMX describes tile maps of any size, including layers and no restrictions on tile sets. Custom properties can be set on most elements. Objects can also be grouped and placed freely. There is also a JSON based file format that is related.