Spectrum services provide a unified interface to many spectral databases, with search by name and coordinates, as well as more advanced queries.

In the following, we search for high-Z quasars from the Sloan survey, and use the Spectrum Services to identify lines.
This example is oriented to a human-driven, visual investigations – however, we point out that NVO is built with web services, so that programmatic access is straightforward at all levels of the NVO.