  Although full interoperativity between theoretical and observational data in
the framework of the Virtual Observatory would be a very desirable achievement,
the current status of VO offers few approaches to handle theoretical models.
TSAP (Theoretical Spectra Access Protocol) has been proposed as a tool to fill
this void, providing a simple scheme to easily operate with th is kind of data.
TSAP is useful not only for synthetic spectra but also for other types of
theoretical data. As an example we show an Isochrone and Evolutionary Tracks
server using TSAP. Finally, we pay special attention to the correct treatment
of the credits an important issue in the field of theoretical models.
