Earth Viewers

This chart compares Google Earth and World Wind against a handful of other software packages which might all be loosely termed "Earth Viewers".  Rough comparisons are drawn to several free (and Free) tools and one commercial one (ArcGlobe) all of which have very different emphases.

  NASA World Wind
(link)
Google Earth
(link)
VTP
(link)
planet-earth.org
(link)
osgPlanet
(OSSIM)
(link)
osgdem/
osgviewer
(link)
ArcGlobe
(link)
ArcGIS Explorer
(link)
Paging of huge datasets yes yes yes yes yes yes yes yes
Streaming over internet yes yes no yes yes yes possible(4) yes
Includes access to high-quality commercial imagery no yes no no no no no yes
Unified coordinate system ("space to face") yes yes no yes yes yes yes yes
Get elevation of camera and cursor no yes yes no no yes? yes yes
Intended for developers
(Open API)
yes no yes not yet yes yes yes
(GIS only)
no
Intended for end-users
(Feature-rich GUI)
yes yes yes yes no no yes yes
Import user elevation data possible¹ no yes possible² yes yes yes yes
Import user image data possible¹ yes (requires
manual georef)
yes possible² yes yes yes yes
Import image data at runtime no no no no no yes yes
Generation/use of datasets
(elevation/imagery)
n/a with GUI
(imagery only)
with GUI yes (how?) with config
script (.kwl)
with command-
line; very slow
with GUI with GUI
Import GIS data no? no (not in
free version)
points and
vectors only
possible no no yes yes
Import 3D Models no yes
(from KML)
yes yes (demo
only)
yes yes yes(3) no
Buildings no yes (simple
extrusion)
yes yes (demo
only)
no no yes (simple
extrusion)
no
Roads no no (only as vectors) yes no no no no (only as vectors) no (only as vectors)
Vegetation no no yes no no yes? (with
osgforest)
yes? no
Create Culture at runtime n/a just placemarks fences, plants,
3D models
no n/a n/a

partial(5)

no
Create GIS features no yes (limited) no no no no yes ?
Free (as in price; gratis) yes yes yes yes yes yes no yes
Free (as in freedom; libre) yes no yes yes yes yes no no
Estimated size of active user community hundreds? hundreds of
thousands
hundreds dozen dozens hundreds? thousands tens of thousands?

¹: Raul Aguilera Hermosilla writes: "World Wind, being open as it is, uses "generic" formats for the data (elevation and images) with a rather awkward (but explained fully within the user groups) tiling scheme. What you can do is either replace or superimpose your elevation files or images. This is not for the end user but anyone with enough patience (to find the appropriate details) can do it.  I haven't had the time to actually do it but from what I saw I am pretty sure it can be done."

²: Chris writes: For planet-earth you use the Rez toolset to generate the elevations+imagery.  You then have to transfer it to server and there is some manual editing to include.  There *is* an interface online to upload it and have it positioned but there are bugs in it at present.

3: Can directly import 3DS, SketchUp, VRML and OBJ file formats, with textures.

4: Streaming: ArcGlobe acts as a client.  Basically for vectors you need one of the server products (ArcIMS, ArcServer or the new image server), or a web server serving a raster file format which supports streaming (ECW and perhaps a few others).

5: ESRI says: "ArcGlobe is an interactive 3D GIS, which means that 3D “culture” objects are treated as symbology attached to point locations.  If you have 3D symbology set up, you can add points to insert/position 3D objects on a terrain surface.  Various people have created add-on interfaces which let you pick the 3D object first, then create a point for it – but these are free extensions, and not in the normal GUI as shipped.  ArcGlobe does not provide a 3D content creation environment for “culture” items.  We generally suggest the use of @Last Software’s SketchUp, because it supports georeferencing.  However, any 3D surface modeler which can export to the 4 supported 3D file formats above should work."