You want to use Flash Remoting with something other than ColdFusion MX, .NET, or J2EE, which are the only three server-side platforms officially supported by Macromedia.
Although the AMF format is not open or documented, it turns out that it is the same format used by remote shared objects. An enterprising individual, Wolfgang Hamann, reverse-engineered the AMF format, allowing developers to build open source libraries to support Flash Remoting in server-side languages not supported by Macromedia.
The AMFPHP project implements a Flash Remoting library for PHP. The Flash Remoting in Perl project (FLAP) implements a Flash Remoting library for Perl. Refer to their web sites (http://amfphp.org and http://www.simonf.com/flap, respectively) for installation, configuration, and support information.
OpenAMF for Java (http://www.openamf.org)