I have looked at IB API and I like it a lot, but im a .net developer so its really easy for me to understand. They have a sandbox where you can "paper trade" or simulate(as best as you can) with real market data, all you need to do is credit your account with 10k to start up, but i think that is standard just opening an account with them, I'm not sure
I have written code that splits electronic trading into 3 modules, one that selects stocks(using multiple independent configurable algorithms), one that manages trades/stops (once they are placed) and also manages portfolio risk and the other, yet to be coded module that actually interacts with IBs API to make and manage trades in the live(or sandboxed) market
just havent got around to finishing it yet, its a big job, way to big for just one developer
