Wikipedia
CppCMS
CppCMS is an open source web application framework for the C++ programming language developed by Artyom Beilis. It is one of very few web frameworks for C++. The primary goal of CppCMS is building performance-demanding web applications. It may also be used for embedded web applications for consumer devices (such as administration consoles for routers, smart devices, etc.. The library is available under multiple licenses: LGPLv3 and a commercial license. It currently targets POSIX-compatible and Windows platforms.
Despite what the name suggests, it is not a content management system.