# GMaps.js — Map Types

You can define many map types from external map services, like OpenStreetMap:

    map.addMapType("osm", {
      getTileUrl: function(coord, zoom) {
        return "http://tile.openstreetmap.org/" + zoom + "/" + coord.x + "/" + coord.y + ".png";
      },
      tileSize: new google.maps.Size(256, 256),
      name: "OpenStreetMap",
      maxZoom: 18
    });

You must define a function called `getTileUrl`, which returns a tile URL according the coordenates in the map.