Smart Quant is kind of dated and not so polished as compared to the major HFT trading offerings
starts at $399/month
Honestly, I am not a fan of this monthly billing model. You put an investment into their API and they could vanish the next day. No thanks. I will review this platform. This just seems to be a nickle and dime you to death time of business. There is some decent documentation to get you started. This does support Interactive Brokers. Has all the basic features but nothing outstanding or eye catching. This seems severely limited as compared to Deltix or X_Trader.
FACEBOOK ACCOUNT and TWITTER. Don't worry as I don't post stupid cat videos or what I eat!