d’Isle Blog posted a succinct comparison of Google Earth and NASA World Wind. The NASA World Wind is similiar to Google Earth in the sense that it renders topological data from LandSat in 3D using graphics hardware and as yet it only works on Windows. They say their primary concern is Education, not commerce, that is the difference.

[…]It is Open Source’d, though written in .NET (not that that’s a terrible thing, necessarily) Their dataset is much better in some ways than Googles and the interface is a little clearer on some things (altitude) and significantly less efficient on others (navigation and data sources)

[…]I idly wonder whether WW played any role in the opening of Keyhole’s licensing. Google’s mission has always been “searching, searching, searching” so it sort of justifies their aquisition but still. World Wind was relatively new, is starting to really get moving. Maybe it just reflects the fact that the world (ahem) is ready for something like it . The data to back it up exists, the open formats behind it are clear enough, and the hardware exists, why not?

Notice that the latest release of NASA World Wind was on May 26, 2005. And you can get it from Sourceforge. Available under the NASA Open Source Agreement.