Hi all, I have some trade ideas and these trade ideas all need some sort of market scanning, historical data back-testing, plotting, decision making, and execution based on my own models and signals. They need some sort of programming and data analysis. I am looking for the best trading software(commercial or open source) that are fast (with realtime calcualtion/monitoring of a large group of stocks in mind), convenient (facilitate the testing of strategies), and extensible(so I can plug in my own criteria, signal and models). Please give me some pointers on both commercial and open source trading software! Is there a comparative study? More ideally, if I could find a good open source trading platform that is already established, I can contribute my part to make it more functional!