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.

E*Trade Web Platform - E*Trade Web Platform is a program that allows users to trade stocks, options, and other securities.

Quantopian - Your algorithmic investing platform

Calypso Platform - Calypso Platform is a comprehensive solution for trading, risk management, and regulatory compliance.

quantra - A public API for quantitative finance made with Quantlib

Finacle Treasury - Finacle Treasury is a comprehensive solution for trading, risk management, and operations.