amfphp

http://amfphp.org/

AMFPHP is a free open-source PHP implementation of the Action Message Format(AMF). AMF allows for binary serialization of Action Script (AS2, AS3) native types and objects to be sent to server side services. AMFPHP is challenged with implementing the entire AMF protocol to be an alternative to Flex Data Services (AMF3) and Flash Remoting (AMF0). AMFPHP allows thin client applications built in languages such as Flash, Flex, and AIR to communicate directly with PHP class objects on the server.

範例
http://www.sephiroth.it/tutorials/flashPHP/flex_remoteobject/index.php
http://www.luar.com.hk/flashbook/archives/001359.php