List of trading platforms with public API

The following table lists some brokers and trading platform vendors who have their API documentation publicly available:

Broker/vendor	URL	Programming languages supported
Interactive Brokers	https://www.interactivebrokers.com/en/index.php?f=1325	C++, Posix C++, Java, and Visual Basic for ActiveX
E*Trade	https://developer.etrade.com	Java, PHP, and C++
IG	http://labs.ig.com/	REST, Java, FIX, and Microsoft .NET Framework 4.0
Tradier	https://developer.tradier.com	Java, Perl, Python, and Ruby
TradeKing	https://developers.tradeking.com	Java, Node.js, PHP, R, and Ruby
Cunningham trading systems	http://www.ctsfutures.com/wiki/T4%20API%2040.MainPage.ashx	Microsoft .NET Framework 4.0
CQG	http://cqg.com/Products/CQG-API.aspx	C#, C++, Excel, MATLAB, and VB.NET
Trading technologies	https://developer.tradingtechnologies.com	Microsoft .NET Framework 4.0
OANDA	http://developer.oanda.com	REST, Java, FIX, and MT4