Paint tile maps, draw vector geometry, and move work between the tools that will not talk to each other. In a browser, with no account and nothing to install.

TMJ, TMX and TSJ, in and out. It joins the pipeline you have instead of asking you to leave it.
SVG from Illustrator or Figma, DXF and DWG from CAD, GeoJSON from a mapping tool — all of it arrives as geometry you can keep editing.
Trace a bitmap into paths, fill a shape with tiles, script the document, export a print-ready PDF or a transparent PNG, edit live with other people.

A drawing in, a tile map out, with the vector geometry, the symbols and the layers intact. Nothing else makes that hop.
Your work stays on your machine unless you ask otherwise — a session you start, or a DWG import you confirm.