So my idea is simple, users have a GUI, with extreme's line of hardware (Switches, Routers, APs, Modules, etc), each device has a description once clicked, and a stripped down and lightweight version of XOS.
Each device then has a GUI for basic configurations like IP settings, and a CLI for more advanced configs like port security, VLANs, routing, VPNs, traffic engineering, etc.
Once a devices are connected and configured, network activity can be visualized from Layer 1 through to Layer 4. And if you're thinking of introducing SDN at a certification level, a stripped down version of an application to function at the Control Plane, etc.
I believe in this kind of learning because when I first decided to adopt a particular vendors technology, they had a Simulator I used to get to know their equipment. With time I learned the commands, and everything else is history