I want to develop a simple OMS application that can manage orders and positions through FIX protocol (ignoring the strategy engine); just wondering; how much time would it take to develop a basic order management system that can connect to IB Gateway and manage orders (overnight/weekends)? The application should be able to handle both equities and futures to start with. How many man days of dev work are we looking at if I were to use C++ and a fix library (say http://www.quickfixengine.org/ or ?...suggestions ) on Linux? What version of FIX should I use? How easy/hard is it to reuse the same application to connect to a different broker... say advantage futures or lime brokerage. Any suggestions can help, thanks.