For my latest project I wanted to add SOAP support into Magento so I can use SOAP calls within my extensions. Doing this on my local xampp install was easy – I just edited the php.ini file and included the php-soap.dll.
On my linux server which is running Plesk 9 it was marginally more involved. I had to follow these steps from the shell prompt:
wget -q -O - http://www.atomicorp.com/installers/atomic |sh
yum install php-soap
service httpd restart
That’s it, I am then able to invoke the SoapClient within my Magento extensions. I use the lib directory to store the wsdl files.