This is Qt 6.6.3 backport that runs on Windows 7 (what?). The repository contains patched source files from the qtbase module.
Approach is based on this [forum thread](https://forum.qt.io/topic/133002/qt-creator-6-0-1-and-qt-6-2-2-running-on-windows-7/60) but better: many improvements amongst important fallbacks to default Qt 6 behaviour when running on newer Windows.
You can use [our prebuild binaries](https://github.com/crystalidea/qt6windows7/releases) (we used Visual C++ 2019 with OpenSSL 3.0.13 statically linked, see [compile_win.pl](https://github.com/crystalidea/qt-build-tools/tree/master/6.6.2) script) or compile Qt yourself using a compiler and build options you need.
### Known issues:
- QRhi using DirectX 11/12 is not ported
- setHighDpiScaleFactorRoundingPolicy(Qt::HighDpiScaleFactorRoundingPolicy::Round) is recommended
The repository shares Qt Community Edition terms which imply [Open-Source terms and conditions (GPL and LGPL)](https://www.qt.io/licensing/open-source-lgpl-obligations?hsLang=en).
