An application programmatic interface (API) is the interface that allows exchange of data between applications or systems.Using APIs helps you to integrate seamlessly into service provider's website to acquire their data/services at real time. There are various service providers across the world that provide free/paid API to integrate and expand their services. A Web service interface is to be created that acts like a web form to pass the information into a web service and display the results in XML format.

For better understanding, below are lists of sites that offer APIs for specific purposes for:

Our list of Rich Internet Application services include: