CocoaHTTPServer

Links:
https://github.com/robbiehanson/CocoaHTTPServer
http://cocoawithlove.com/2009/07/simple-extensible-http-server-in-cocoa.html

XML-RPC

Link: http://en.wikipedia.org/wiki/XML-RPC

Intro: XML-RPC is a remote procedure call (RPC) protocol which uses XML to encode its calls and HTTP as a transport mechanism.[1] "XML-RPC" also refers generically to the use of XML for remote procedure call, independently of the specific protocol. This article is about the protocol named "XML-RPC".

C++ Tool: (tested) http://xmlrpcpp.sourceforge.net/