Today, while looking into the new Google Maps Docs, I ran across the Styled Maps. They are quite powerful! While Cloudmade offers a similar service for a while, I didn’t expect Google to offer this, and for free.
A bit of technical background: these mapping services work by splitting the world into tiles. The whole world takes millions of tiles (depending on zoom level), and thus hundreds of gigabytes to render and store. While rendering and storing the world once isn’t that much effort for Google, rendering it in as many styles as it’s customers come up with does take quite a bit of processing power (For more background on the subject: See my Thesis on LBS)

While I have run a tile render server in the past, this was always an expensive, and not that scalable operation. So I’m suprised (but happy!) that Google now offers this to the world, for free! In just a few minutes, I was able to create the demo Waterworld shown above.

More examples can be seen on the Google Maps blog

For the last few months, I have been involved in the open source mapping project Openstreetmap. It can be described as an open-source Google maps alternative: They collect the world, and have their database open for anybody to use and edit. So instead of just being able to view the maps, you are also able to get the underlying data. The database consists of basic nodes and vectors, that describe the whole world. These descriptions can be rendered into graphics, by several renderers. One of the main renderers (and the one used on the standard map on openstreetmap.org) is Mapnik. It loads the data from the database, and can output graphical maps, with styles described in stylesheets.

Until now, modifying those stylesheets was often a tedious task of edditing files, and pointing a renderer at them, often at some server (as not many users have the nescascarry software installed to render these maps).

To ease this process I build an online render tool: You can edit the style file, choose a bounding box, and immediately see the results online. A screenshot is shown above: The editor can be found at http://tile.openstreetmap.nl/~panman/styledit/

If you build a nice style, let me know!

Update

Unfortunately, this specific post has been the target of a LOT of spam, so I closed the comments. If you want to comment on it, please send me an email. 

We are sorry (served from sorry.google.com )

Currently all satellite images on Google maps, and ALL sites that use Google Maps (like ours),  are down.

Not that it’s a huge issue: the street view still works. But still: This is the first time that I can remember that (part of) a google service is completley down, for all users. It also shows how we just assume stuff like this always works (and how the all the web 2.0 mashups are dependent on their data suppliers…)