-Two popular operating systems are Windows and Linux -Some popular programming languages are C++ java C# Python -Never used it but based on the description OANDA provides a platform for trading FX and provide an API for Programming languages: java C# and C++ on Operating systems: windows and linux. They do not provide an API for python Using the API (Application Programming Interface) provided from OANDA you can write your own application in any of the 3 languages they support and interface with the platform to get quotes, place orders, get historical data etc.... The developer on the link you provided has created python bindings (other word: adapter, wrapper) for the linux operating system and provides them for free. That means, he wrote code that provides a python API for OANDA platform by internally using the C++ API. In other words, you can code using Python language and internally your code will use the C++ api to 'talk' to the platform. This is a good solution if you are a python programmer and don't want to learn any of the other languages. The developer makes clear that he only provides the python bindings/wrapper. You will have to get the C++ api ( that is used by the Python wrapper he wrote) on your own from OANDA (pay any fees, subscribe to the service etc..) He wrote the python wrapper for linux operating system, and gives it away for free (GPL license). If you want the python wrapper for windows, he can write it but he will need to be compensated for his time.