> For the complete documentation index, see [llms.txt](https://docs.novaflowos.com/start/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.novaflowos.com/start/qt6-qml-book/readme/ch18-extensions/extending-qml.md).

# Extending QML with C++

Creating application using only QML can sometimes be limiting. The QML run-time is developed using C++, and the run-time environment can be extended, making it possible to make use of the full performance and freedom of the surrounding system.