Soup is a SOAP (Simple Object Access Protocol) implementation in C.

It provides a queued asynchronous callback-based mechanism for sending and
servicing SOAP requests, and a WSDL (Web Service Definition Language) for C
compilers which generates client stubs and server skeletons for easily
calling and implementing SOAP methods.  It uses GLib and is designed to work
well with GTK applications.

Features:
  * Completely Asynchronous
  * Connection cache
  * HTTP chunked transfer and persistent connections
  * Authenticated HTTP, SOCKS4, and SOCKS5 proxy support
  * SSL Support using OpenSSL
  * Apache module server support
  * Client digest authentication