XML-RPC is a very straightforward and effective data transport mechanism. Requests and responses are formatted in a common way. Clients and service providers can easily implement this simple protocol. PHP has a group of XML-RPC functions that are made for working with XML-RPC data.
PHP’s XML-RPC functions are documented at: http://www.php.net/manual/en/ref.xmlrpc.php. The collection is small but invaluable. They can be grouped into functions that enable PHP applications to be XML-RPC clients, or functions that create PHP-powered XML-RPC services. These functions are available, if PHP was compiled with the -with-xmlrpc option.
Note
If you check out the official PHP XML-RPC documentation, you will see they have been marked “experimental”. However, they have been around since PHP 4.1 and are long considered stable and reliable for production usage.
To make your mashup, you need to know how to create an XML-RPC request, how to call the service, and how to process the...