XML-RPC is a protocol that uses XML messages to perform Remote Procedure Calls. Requests are encoded in XML and sent via HTTP POST; XML responses are embedded in the body of the HTTP response.

More succinctly, XML-RPC = HTTP + XML + Remote Procedure Calls.

Because XML-RPC is platform independent, diverse applications can communicate with one another. For example, a Java client can speak XML-RPC to a Perl server.

To get a quick sense of XML-RPC, here is a sample XML-RPC request to a weather service (with the HTTP Headers omitted):

  weather.getWeather  10016  

The request consists of a simple element, which specifies the method name (getWeather) and any method parameters (zip code).

Here is a sample XML-RPC response from the weather service:

    65   

The response consists of a single element, which specifies the return value (the current temperature). In this case, the return value is specified as an integer.

In many ways, XML-RPC is much simpler than SOAP, and therefore represents the easiest way to get started with Web services.

The official XML-RPC specification is available at XML-RPC.com. Dozens of XML-RPC implementations are available in Perl, Python, Java, and Ruby. See the XML-RPC home page for a complete list of implementations.

Thanks!
Manoj [InfoAxon Technologies Ltd.]