Originally, the National Science Foundation (NSF) funded the information technology research that created the basic NVO infrastructure through a multi-organization collaborative effort.
As of October 1, 2014, funding ceased for the National Virtual Observatory (NVO) and all code and digital assets of the project were made publicly available at the VAO Closeout Repository.
[1] The NVO was conceived to allow scientists to grapple with the enormous growth in astronomical data resulting from significant advances in telescope, detector, and computer technologies.
Investigators acquired existing astronomical data from a variety of observatory archives through “virtual instruments”, that is, computer interfaces, tools, and services.
The NVO Closeout Repository provides access to a variety of additional data from nearly every astronomical research facility, observatory, and telescope across the globe.