Oh ok, I thought they had some kind of set of PCs rendering out the vector data and would serve up the image. As I read it they were saying that there exists these huge databases of vector data and they had some kind of capability of interpreting it to tiles and you grab the tiles. So you have to host that capability as well then. Re-reading the article with your additional explanation does give me a different impression now. So I guess this is more of a C or Ruby based simple API with limited scope for what would already exist in a more extensive fashion, if you could be bothered to set it all up, but either way, your server will do all of the image rendering and generate the tile. Possibly still useful but it sounds like you will still need to run a server and still need to download the multi gigs of vector data to make it work.

Thanks Hai b.t.w...