What is the XMLRPC?

XML-RPC is a technique by which one could execute remote procedure calls (RPC) to software written in different languages and running on different environments. XML-RPC uses the standard XML coding. Simply put, its nothing more than a set of specifications and implementations that allow software running on a variety operating systems, running in different environments to make procedure calls over the Internet. For calls and sends messages, the protocol used is the Hypertext Transfer Protocol (HTTP). Developers commonly use XML-RPC to develop Web services (e.g) blogging. A good feature of XML-RPC is that the libraries function in firewall or proxied environments as the transport is over a HTTP layer!

Just as you make standard local procedure calls in your local machine, the RPC is a very simple extension to the local procedure call idea! The RPC creates the connections between procedures that are running in different applications, or on different machines. Conceptually, there's no difference between a local procedure call and a remote one, but they are implemented differently, perform differently and are used for different things.

Remote calls are streamlined into a format that can be understood on the other side of the connection. As long as two machines agree on a format, they can talk to each other. That's why Windows machines can be networked with other Windows machines, and Macs can talk to Macs, etc. The value in a standardized cross-platform approach for RPC is that it allows Unix machines to talk to Windows machines and vice versa.

Tu summarize, XML RPC is a gluing element to different implementations on different machines via web service using the HTTP layer.