1.4.24. Can the user be asynchronously notified when a long running query terminates?

There is no off-the-shelf API for this but making an adaptation of the SPARQL endpoint that could proceed after the client disconnected and, for example, could send results by email is trivial. Since SOAP and REST Web services can be programmed directly in Virtuoso's stored procedure language, implementing and exposing this type of application logic is easy.