a language analysis tool where you can simulate the behaviour of the chips and memory, you can see the AST of your custom grammar or existing languages as well as stepping through the different compiler optimizations and actually can snapshot a the memory and see the chip logic gates and registers.... so you can understand the codes and vms from low level to executions cycle by cycle or execution by execution :) just giving fresh students the tools to really see whats going on and learn about the correlations and such things :D