Wealth-Lab Developer 5 will not provide any other broker API by the decision of Fidelity. All humans know, WLD 3 and 4 is terrible slow. If you run the real-time scans of multi-markets on the tick level, it's high probability that you become the murderer of your PC. So these days I'm looking for a new platform. I don't like to be the lab rat for those platforms with little customers now, even if it may be the next Microsoft in the future. It seems that the following several ones have sold to many experienced system traders. AmiBroker http://www.amibroker.com/features.html MultiCharts http://www.tssupport.com/multicharts/features/ MetaTrader http://www.metaquotes.net/advantages I very appreciate your reviews if you have some experiences of more than one of them.