I think teacher should stick with VB.NET. Why? Because it enables students who like experimenting to get results quickly and this is extremely important if you want to get children enthusiastic about anything. Yes, python is free and open, and I bet many of the students who will become interested in programming will switch away from VB.NET anyway, but right now at this moment the ability to put a button on form with a mouse, doubleclick the button and write in a simple line to display messagebox of swearwords on click, is the most important factor of them all. And it looks like real, professional application window, I mean how cool is that?