From World Wind Wiki
Add-ons allow you to view trails and other areas of interest. World Wind Central has a full alphabetical list of add-ons for NASA World Wind.
Plug-ins allow you to use extra features not provided with World Wind. For a list of plug-ins compatible with World Wind 1.4 see the 1.4 plug-ins list.
Recently Added or Updated
- Castles (updated 2009-04-18)
- Tour de France (updated 2008-06-30)
- Saturn (updated 2008-05-29)
- Climate Mapper (added 2008-05-19)
- OpenStreetMap (added 2008-03-27)
- Natural Earth (added 2008-02-18)
Full list of Add-ons
Many more add-ons are available at the full list.
The Add-on Launchpad page gives you a good introduction to add-ons and contains many example add-ons.
The creating add-ons page provides detailed information about the different types of add-ons and explains how you can create them yourself.