QuantConnect - QuantConnect provides a free algorithm backtesting tool and financial data so engineers can design algorithmic trading strategies. We are democratizing algorithm trading technology to empower investors.
Quantopian - Your algorithmic investing platform
CloudQuant - Crowd based algorithmic trading development and backtesing for stock market trading.
quantra - A public API for quantitative finance made with Quantlib
Streak.world - Streak.world is one of the leading algo trading platforms, allowing you to design an algorithm to automate your trading strategies without any coding skills needed.
Algoriz - Algoriz uses artificial intelligence to build trading algorithms.