We ‘ve been using nuSOAP as a PHP web services framework for quite some time. It’s just a couple of PHP files meaning that you only need to include it in your php code, it’s easy to code and elegant. You just register functions and the framework takes care of creating WSDL (through a ?wsdl binding in your php web service pages) and all the SOAP communication with minimal effort. The problem is that it’s not maintained anymore and thus there’s no real support for the WS-*specification¬† stack. We ‘re particularly interested in the WS-Security in our case. WSO2 provides a PHP framework that provides all that (based on the Apache Axis2/C code). The API is quite easy to understand, supports using REST style calls and consuming WSDL. The WSDL mode is the easiest to use for writing both the client and the server but requires having the WSDL file ready.