QtWebSockets is a pure Qt implementation of WebSockets - both client and server. It is implemented as a Qt add-on module, that can easily be embedded into existing Qt projects. It has no other dependencies than Qt.
Qt 5.x
Checkout the source code from code.qt.io Go into the source directory and execute:
qmake make make install
The last command will install QtWebSockets as a Qt module.
To use, add websockets to the QT variable.
QT += websockets
QtWebSockets is compliant with RFC6455 and has been tested with the Autobahn Testsuite.