Marble is a free geographical world atlas program for KDE which can show the world as a 3D globe. It is included in kdeedu as of KDE 4 and is also availble for KDE 3.x as an optional package.
 Extremely flexible
The KDE Marble application is essentially the QT Marble Widget with a KDE GUI. Other software has already begun to leverage this ability to show a mapped globe using a clean free software library. Vidalia, for example, can now show the Tor networks routers on a 3D earth using the Marble Widget.
 The earth at your fingertips
Marble allows you to spin the globle, zoom in on the area you want and view where the citizes are, the lakes are, and any other thing you can find out using a basic map. It's kind of like the popular Google Earth software, with one major difference: Marble uses a static world map, where as Google Earth has satellite images, air photo's, and so on.
You can't "zoom in" very far before the 3D map gets so blurry it's redicilous, and there is, as already mentioned, no fancy aireal photos or something fancy like that, there's no nothing except the very basic map of the world which you can zoom in and out. Well, there is one thing, you can choose between a map of the earth during the day, the night and the view from space. But they are all just plain maps.
It's kind of like having a good old globus on your computer which you can spin and zoom. The map seems accurate, the cities appear to be marked where they are supposed to be (But I don't guarantee they are, I'm not a geo-scientest).
Marble supports online mapping sources such as OpenStreetMap and standard kml files. This file standard is used by common mapping software such as Google Earth and Google Maps.
 In bullet summary, we know
- Marble is great for educational usage.
- It lacks all kinds of fancy features. It's also not Google Earth.
- It does give you a nice spinning globus with a map-o-the-earth on your computer and it does allow you to look up which cities are where, and such.
- Official story: http://edu.kde.org/marble/