Is there a way to do this with Python or Ruby? I could just as well program this in C#, but I have a friend who can code a little, but doesn't really need everything in C# to do what he wants. The value add of offering the simulator, including the taking into account the bid/ask prices and a stochastic model for latency. Combine this with a web based code editor and easy hosting, and I think this would be a viable product.