Php – good alternative to PHP’s SOAP extension?

phpsoap

I have a project which relies heavily on PHP's SOAP extension. It's great, and works wonderfully.

However, I have to deploy a version of the software on a server that does NOT have the extension (it is PHP5 though). At this time, changing hosts is not an option; and it looks like installing the extension is also not an option.

Is there a pure PHP implementation of a SOAP client library that I can use in its place?

I do not expect a perfect drop-in replacement–I'm completely prepared to mod a bunch of the code–but something that I can work with.