Works on Windows, MacOS, and on mobiles and tablets too - you lucky Android and iOS people.
You will need to have Google Earth installed to use this.
You'll need Google Earth installed.
If you are using a PC or a Mac, you can download Google Earth here
If you have an iPhone or an iPad, you can download Google Earth from the App Store.
Android phone or tablet users, you may well have Google Earth anyway, but you should be able to download it if you don't.
The mobile/tablet version doesn't quite do all the things the desktop version does, but it's still pretty good.
See the 2013 Map!
If this does not open automatically, use 'Open' in Google Earth, and find the GlastoEarth.kml file that has been downloaded.
Updates Are Automatic! Once you have followed the link above, you will always get the latest version when you open Google Earth. There's no need to download again. Which is nice.