Technically, the 15 pin high density connectory that is on the adapter is S-VGA. I know older Macs used a 9 Pin VGA connector. It's the monitors that have a 9 Pin VGA connector that probably won't work.
More information on the various Video modes and connectors can be found
here.
And I know some people have some really old equipment. Of course since 9-Pin VGA monitors haven't been made in years, S-VGA devices and cabling started being call VGA. Language transformation in action.