I am playing with Trading Technologies platforms and C++ API. Overall it is a big wow and very ready for high frequency trading aka HFT
but one word it is very very pricey. Boo to that but it is quite powerful. I will report back as I find things out. Just know this is institutional not for little people like us.
NOTE I now post my TRADING ALERTS into my personal FACEBOOK ACCOUNT and TWITTER. Don't worry as I don't post stupid cat videos or what I eat!