DevShed has a new article posted today - a tutorial walking you through a sort of brief history of SOAP support in PHP and some working examples of each - NuSOAP, PEAR::SOAP and PHP's SOAP extension.
SOAP (Simple Object Access Protocol) provides a flexible communication layer between applications, regardless of platform and location. As long as both the server and the client speak SOAP, they can communicate. A PHP-based web application can ask a Java database application to get some information. In this article we will try to focus on different methods of developing SOAP web service clients in PHP.
They start with a look at NuSOAP and the creation of both a client and server (as well as an example on how to use some of its debugging. Next up is PEAR::SOAP, a powerful package that simplifies much of the same functionality NuSOAP has to offer. Finally, they get to the most recent SOAP functionality for PHP, the PHP SOAP extension that comes loaded with PHP5 installations by default. This includes a brief overview of its API and code examples that, in a few lines, do what takes the others twice as much.