Do you mean Destinator? Destinator is the commercial software on which MapMonkey and FreeDrive are both based.
You need to purchase Destinator and the US maps for it, as well as the SDK, if I'm not mistaken. It is certainly comparable to iGuidance, but I've heard the Destinator US maps aren't as good as iGuidance maps.
S&T isn't a nav program, and is pretty lousy for in-car use. The maps are good and S&T does give good directions, however.