From World Wind Wiki
NOSA: NASA Open Source Agreement (see "Software Agreement")
NASA World Wind.NET and NASA World Wind Java, under the NASA Open Source Agreement (NOSA) license, allow for anyone to make 'changes to the core' and redistribute. This 'core' will necessarily fall under the NOSA. But, this *does not restrict* the ability for third-parties to combine the World Wind core with proprietary extensions or applications that leverage this core.
'Core' refers to the NASA World Wind source code released publicly. Any change to the publicly released source code, i.e., the World Wind core, constitutes a change that falls under the NOSA.
Unlike the GPL, the NOSA does not seek to define any encumbrances other than that changes to the core go into the public domain of the NOSA. These terms are less restrictive than the GPL.
Allowed Core Change: You wish to embed or extend NASA World Wind and commercially distribute this 'package.' This might involve some changes to the core to optimize that use. The code changes made to the World Wind core would fall under the NOSA, but this does not in any way apply to the rest of any software 'package' external to the World Wind core as it might be embedded or extended in concert with the World Wind core.
Not-Allowed Core Change: The NOSA does restrict 'locking-up' the World Wind core, i.e., making changes to the core and then distributing that core as a proprietary application. Any code placed into the World Wind core must always remain accessible (open source) and non-proprietary per the NOSA.
If World Wind code is mixed with other code, this is a derivative product and would necessarily fall under the NASA Open Source Agreement (NOSA).
If you create a package (combine versus derived) of World Wind along with other distinct and separately coded entities, be they libraries, modules, applications, etc., that is allowed and remains unaffected by the NOSA. These distinct and separately coded events can be proprietary or otherwise. The only caveat to this package is that any code that might be added to the World Wind core itself, to help integrate these other external software entities, would necessarily fall under the NOSA. But the NOSA would have no bearing on the other distinct and separately coded entities, and in no way encumber their intellectual property (IP) or commercial nature.
Allowed Use of World Wind: The NOSA license encourages evolution of the code base (core). The NOSA also encourages commercial use by allowing for the core (i.e., World Wind SDK) to be embedded into other proprietary applications or extended with proprietary modules or data. The value of the World Wind SDK will increase as the open source community helps to evolve the World Wind core to serve geospatial visualization needs. These addressed needs can be proprietary, as when World Wind is extended or embedded with *separate* modules, data or applications.
Again, any extended or embedded modules or applications *external* to the World Wind core, even though they may have dependencies on the World Wind core, can be intellectual property and are free to be commercially marketed, even as a package distributed with changes to the World Wind SDK (core). Only the changes to the World Wind core fall under the NOSA. So, repeating now for emphasis, the World Wind core is free to be 'packaged' by third parties with proprietary modules or proprietary applications. Distribution of this 'package' commercially or otherwise, only requires that changes to the World Wind core remain under the NOSA license.
We invite the community to support NASA in evolving the core so that it better serves the geospatial visualization needs of any enterprise.