[drd]

I think it is better to call it model-based development rather than visual programming. Apart from those visual tools (e.g. Alice) which can be used to teach children the programming concepts, there are serious tools such as Simulink and SCADE (missing from the list) which are used to develop safety-critical applications in medical and aerospace fields. The reason to use these tools is to allow experts in other disciplines to specify an abstraction of their designs for computer.