gsoap and apache
http://www.aberger.at/SOAP/apache_index.html

http://programming.linux.com/programming/05/02/16/1947220.shtml?tid=63&tid=67&tid=68
quoted:
Whatever your reason, let's assume you have some code written in C that needs to be called via SOAP. You can either use one of the SOAP frameworks available for Java and use JNI to call it, or else you can set up a native C SOAP environment for your code. The foremost free SOAP solution is the Apache Foundation's Axis. Most people know the Java version, but there is also a full-featured C version available and this is the one we will be working with.

Unfortunately, installing Axis-C++ can be tricky, especially the integration with the Apache web server. The following step-by-step guide will enable you to get a production-level installation up and running quickly on GNU/Linux. After installing the server, the rest of the article will describe the development and deployment of a basic SOAP service.
- posted by Pop @ 5:36 PM