NuSOAP: An easy to use SOAP Stack for PHP

If you need to make your PHP-based application make SOAP calls into an application with a WSDL-based interface, consider using NuSOAP. It is simple to use and will get you up and running within minutes. The best part is that you dont have to install any new PHP Extensions. All you have to do is to download and unzip the NuSOAP files in your PHP-enabled web server and you are ready to go.

A couple of good resources for getting started with NuSOAP are:

1. NuSOAP Home.
2. Introduction to NuSOAP.