Windows 7 and Windows Server 2008 R2 introduces a new framework for building web services in C++ code. Windows Web Services API (WWSAPI) supports core set of protocols for SOAP-based web services. Developers can use WWSAPI in apps where they need to use native C/C++ code and they cannot take dependency on .Net Framework. Solutions built with this API require significantly less memory than WCF on client side. On server side, API allows developers to achieve much higher throughput than WCF. You can find links to all online resources here.
More info: SDK blog