Here's a map showing the world's coastlines using the spherical Mercator projection ("web Mercator"). You can load extra maps very easily using the CartoType framework's LoadMap function; the only requirement is that the extra maps have the same projection and resolution, which in this case is one map unit per projected meter. I made these images using the Cartotype Windows demo, which has the option 'Open in current map...' in the File menu.
First I load a map of Greece and zoom in to show that it's really there:
then Bulgaria:
and China:
and finally I change the style sheet and zoom into Shanghai: