As part of the XACML Interoperability preparations, I wrote client code that uses SAAJ 1.3 to build a soap message and send it across to any endpoint that supports scenario 1 of the interoperability process. I basically pass an endpoint url to this set of program code and I get a soap response from the end point, which when processed yield a xacml decision.
Basically, I was able to call the end-points of BEA,IBM, JBoss/RedHat,Oracle, Securent and Jericho Systems with the same piece of client code and the same SOAP request (which internally contains the XACMLAuthDecisionQuery Node) and get a PERMIT decision, irrespective of the implementation details of the XACML implementation at each of these endpoints.
I would like to salute standards that make interoperability a reality. The same salute goes to the faucet makers, who follow standards and who came to my rescue when the hand sprayer from the kitchen tap at my house snapped. All I had to do was, go to Home Depot and buy a generic one.