Version 1.0 of SWX PHP and SWX ActionScript Library were released not log ago.
SWX is the native data format for the Flash Platform.
SWX RPC is a remote procedure call protocol encoded in SWX. It’s simple enough that you can get up and running with it in about five minutes. SWX RPC is perfect for building mashups (with easy-to-use APIs for Flickr, Twitter, and others), mobile applications (Flash Lite 2.0 and 2.1), and other data-driven Flash sites and applications.
New: Play with the SWX PHP 1.0 Start Page live on this server!
Find out more about it here:
http://swxformat.org/